You need to edit the MAC-Features.cfg file under Basefile-Edit in Endpoint Manager. Add a section called lineKey following the instructions at the top of the page (File=features, Section=TOP, Parameter=likeKey, Value=PARENT).
Then create the subitems as directed in the link in your post. Or, you can look at the Polycom UC Software Version 5.4.0 Administrator Guide on page 164.
Relevant parts of my resulting MAC-Features.cfg file is below for reference. The newly created lineKey entries are at the bottom of the file.
#Configuration automatically generated via the EndPoint Module
DO NOT HAND MODIFY THIS FILE!
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<!-- Generated features.cfg Configuration File -->
<polycomConfig xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="polycomConfig.xsd">
<acd
acd.reg="1"
acd.stateAtSignIn="1"
acd.1.unavailreason.active="0"
acd.1.unavailreason.codeName=""
acd.1.unavailreason.codeValue=""
acd.2.unavailreason.active="0"
acd.2.unavailreason.codeName=""
acd.2.unavailreason.codeValue=""
>
</acd>
<attendant
attendant.reg="1"
attendant.ringType="ringer1"
attendant.uri=""
attendant.resourceList.1.address="__b1value__"
attendant.resourceList.1.label="__b1label__"
attendant.resourceList.1.type="__b1type__"
attendant.resourceList.2.address="__b2value__"
attendant.resourceList.2.label="__b2label__"
attendant.resourceList.2.type="__b2type__"
attendant.resourceList.3.address="__b3value__"
attendant.resourceList.3.label="__b3label__"
attendant.resourceList.3.type="__b3type__"
attendant.resourceList.4.address="__b4value__"
attendant.resourceList.4.label="__b4label__"
attendant.resourceList.4.type="__b4type__"
attendant.resourceList.5.address="__b5value__"
attendant.resourceList.5.label="__b5label__"
attendant.resourceList.5.type="__b5type__"
attendant.resourceList.6.address="__b6value__"
attendant.resourceList.6.label="__b6label__"
attendant.resourceList.6.type="__b6type__"
attendant.resourceList.7.address="__b7value__"
attendant.resourceList.7.label="__b7label__"
attendant.resourceList.7.type="__b7type__"
attendant.resourceList.8.address="__b8value__"
attendant.resourceList.8.label="__b8label__"
attendant.resourceList.8.type="__b8type__"
attendant.resourceList.9.address="__b9value__"
attendant.resourceList.9.label="__b9label__"
attendant.resourceList.9.type="__b9type__"
attendant.resourceList.10.address="__b10value__"
attendant.resourceList.10.label="__b10label__"
attendant.resourceList.10.type="__b10type__"
attendant.resourceList.11.address="__b11value__"
attendant.resourceList.11.label="__b11label__"
attendant.resourceList.11.type="__b11type__"
attendant.resourceList.12.address="__b12value__"
attendant.resourceList.12.label="__b12label__"
attendant.resourceList.12.type="__b12type__"
attendant.resourceList.7.address="__b7value__"
attendant.resourceList.7.label="__b7label__"
attendant.resourceList.7.type="__b7type__"
attendant.resourceList.8.address="__b8value__"
attendant.resourceList.8.label="__b8label__"
attendant.resourceList.8.type="__b8type__"
attendant.resourceList.9.address="__b9value__"
attendant.resourceList.9.label="__b9label__"
attendant.resourceList.9.type="__b9type__"
attendant.resourceList.10.address="__b10value__"
attendant.resourceList.10.label="__b10label__"
attendant.resourceList.10.type="__b10type__"
attendant.resourceList.11.address="__b11value__"
attendant.resourceList.11.label="__b11label__"
attendant.resourceList.11.type="__b11type__"
attendant.resourceList.12.address="__b12value__"
attendant.resourceList.12.label="__b12label__"
attendant.resourceList.12.type="__b12type__"
attendant.resourceList.13.address="__b13value__"
attendant.resourceList.13.label="__b13label__"
attendant.resourceList.13.type="__b13type__"
attendant.resourceList.14.address="__b14value__"
attendant.resourceList.14.label="__b14label__"
attendant.resourceList.14.type="__b14type__"
attendant.resourceList.15.address="__b15value__"
attendant.resourceList.15.label="__b15label__"
attendant.resourceList.15.type="__b15type__"
attendant.resourceList.16.address="__b16value__"
attendant.resourceList.16.label="__b16label__"
attendant.resourceList.16.type="__b16type__"
attendant.resourceList.17.address="__b17value__"
attendant.resourceList.17.label="__b17label__"
attendant.resourceList.17.type="__b17type__"
attendant.resourceList.18.address="__b18value__"
attendant.resourceList.18.label="__b18label__"
attendant.resourceList.18.type="__b18type__"
attendant.resourceList.19.address="__b19value__"
attendant.resourceList.19.label="__b19label__"
attendant.resourceList.19.type="__b19type__"
attendant.resourceList.20.address="__b20value__"
attendant.resourceList.20.label="__b20label__"
attendant.resourceList.20.type="__b20type__"
attendant.resourceList.21.address="__b21value__"
attendant.resourceList.21.label="__b21label__"
attendant.resourceList.21.type="__b21type__"
attendant.resourceList.22.address="__b22value__"
attendant.resourceList.22.label="__b22label__"
attendant.resourceList.22.type="__b22type__"
attendant.resourceList.23.address="__b23value__"
attendant.resourceList.23.label="__b23label__"
attendant.resourceList.23.type="__b23type__"
attendant.resourceList.24.address="__b24value__"
attendant.resourceList.24.label="__b24label__"
attendant.resourceList.24.type="__b24type__"
attendant.resourceList.25.address="__b25value__"
attendant.resourceList.25.label="__b25label__"
attendant.resourceList.25.type="__b25type__"
attendant.resourceList.26.address="__b26value__"
attendant.resourceList.26.label="__b26label__"
attendant.resourceList.26.type="__b26type__"
attendant.resourceList.27.address="__b27value__"
attendant.resourceList.27.label="__b27label__"
attendant.resourceList.27.type="__b27type__"
attendant.resourceList.28.address="__b28value__"
attendant.resourceList.28.label="__b28label__"
attendant.resourceList.28.type="__b28type__"
attendant.resourceList.29.address="__b29value__"
attendant.resourceList.29.label="__b29label__"
attendant.resourceList.29.type="__b29type__"
attendant.resourceList.30.address="__b30value__"
attendant.resourceList.30.label="__b30label__"
attendant.resourceList.30.type="__b30type__"
attendant.resourceList.31.address="__b31value__"
attendant.resourceList.31.label="__b31label__"
attendant.resourceList.31.type="__b31type__"
attendant.resourceList.32.address="__b32value__"
attendant.resourceList.32.label="__b32label__"
attendant.resourceList.32.type="__b32type__"
attendant.resourceList.33.address="__b33value__"
attendant.resourceList.33.label="__b33label__"
attendant.resourceList.33.type="__b33type__"
attendant.resourceList.34.address="__b34value__"
attendant.resourceList.34.label="__b34label__"
attendant.resourceList.34.type="__b34type__"
attendant.resourceList.35.address="__b35value__"
attendant.resourceList.35.label="__b35label__"
attendant.resourceList.35.type="__b35type__"
attendant.resourceList.36.address="__b36value__"
attendant.resourceList.36.label="__b36label__"
attendant.resourceList.36.type="__b36type__"
attendant.resourceList.37.address="__b37value__"
attendant.resourceList.37.label="__b37label__"
attendant.resourceList.37.type="__b37type__"
attendant.resourceList.38.address="__b38value__"
attendant.resourceList.38.label="__b38label__"
attendant.resourceList.38.type="__b38type__"
attendant.resourceList.39.address="__b39value__"
attendant.resourceList.39.label="__b39label__"
attendant.resourceList.39.type="__b39type__"
attendant.resourceList.40.address="__b40value__"
attendant.resourceList.40.label="__b40label__"
attendant.resourceList.40.type="__b40type__"
attendant.resourceList.41.address="__b41value__"
attendant.resourceList.41.label="__b41label__"
attendant.resourceList.41.type="__b41type__"
attendant.resourceList.42.address="__b42value__"
attendant.resourceList.42.label="__b42label__"
attendant.resourceList.42.type="__b42type__"
attendant.resourceList.43.address="__b43value__"
attendant.resourceList.43.label="__b43label__"
attendant.resourceList.43.type="__b43type__"
attendant.resourceList.44.address="__b44value__"
attendant.resourceList.44.label="__b44label__"
attendant.resourceList.44.type="__b44type__"
attendant.resourceList.45.address="__b45value__"
attendant.resourceList.45.label="__b45label__"
attendant.resourceList.45.type="__b45type__"
attendant.resourceList.46.address="__b46value__"
attendant.resourceList.46.label="__b46label__"
attendant.resourceList.46.type="__b46type__"
attendant.resourceList.47.address="__b47value__"
attendant.resourceList.47.label="__b47label__"
attendant.resourceList.47.type="__b47type__"
attendant.resourceList.48.address="__b48value__"
attendant.resourceList.48.label="__b48label__"
attendant.resourceList.48.type="__b48type__"
attendant.resourceList.49.address="__b49value__"
attendant.resourceList.49.label="__b49label__"
attendant.resourceList.49.type="__b49type__"
attendant.resourceList.50.address="__b50value__"
attendant.resourceList.50.label="__b50label__"
attendant.resourceList.50.type="__b50type__"
attendant.resourceList.51.address="__b51value__"
attendant.resourceList.51.label="__b51label__"
attendant.resourceList.51.type="__b51type__"
attendant.resourceList.52.address="__b52value__"
attendant.resourceList.52.label="__b52label__"
attendant.resourceList.52.type="__b52type__"
attendant.resourceList.53.address="__b53value__"
attendant.resourceList.53.label="__b53label__"
attendant.resourceList.53.type="__b53type__"
attendant.resourceList.54.address="__b54value__"
attendant.resourceList.54.label="__b54label__"
attendant.resourceList.54.type="__b54type__"
attendant.resourceList.55.address="__b55value__"
attendant.resourceList.55.label="__b55label__"
attendant.resourceList.55.type="__b55type__"
attendant.resourceList.56.address="__b56value__"
attendant.resourceList.56.label="__b56label__"
attendant.resourceList.56.type="__b56type__"
attendant.resourceList.57.address="__b57value__"
attendant.resourceList.57.label="__b57label__"
attendant.resourceList.57.type="__b57type__"
attendant.resourceList.58.address="__b58value__"
attendant.resourceList.58.label="__b58label__"
attendant.resourceList.58.type="__b58type__"
attendant.resourceList.59.address="__b59value__"
attendant.resourceList.59.label="__b59label__"
attendant.resourceList.59.type="__b59type__"
attendant.resourceList.60.address="__b60value__"
attendant.resourceList.60.label="__b60label__"
attendant.resourceList.60.type="__b60type__"
attendant.resourceList.61.address="__b61value__"
attendant.resourceList.61.label="__b61label__"
attendant.resourceList.61.type="__b61type__"
attendant.resourceList.62.address="__b62value__"
attendant.resourceList.62.label="__b62label__"
attendant.resourceList.62.type="__b62type__"
attendant.resourceList.63.address="__b63value__"
attendant.resourceList.63.label="__b63label__"
attendant.resourceList.63.type="__b63type__"
attendant.resourceList.64.address="__b64value__"
attendant.resourceList.64.label="__b64label__"
attendant.resourceList.64.type="__b64type__"
attendant.resourceList.65.address="__b65value__"
attendant.resourceList.65.label="__b65label__"
attendant.resourceList.65.type="__b65type__"
attendant.resourceList.66.address="__b66value__"
attendant.resourceList.66.label="__b66label__"
attendant.resourceList.66.type="__b66type__"
attendant.resourceList.67.address="__b67value__"
attendant.resourceList.67.label="__b67label__"
attendant.resourceList.67.type="__b67type__"
attendant.resourceList.68.address="__b68value__"
attendant.resourceList.68.label="__b68label__"
attendant.resourceList.68.type="__b68type__"
attendant.resourceList.69.address="__b69value__"
attendant.resourceList.69.label="__b69label__"
attendant.resourceList.69.type="__b69type__"
attendant.resourceList.70.address="__b70value__"
attendant.resourceList.70.label="__b70label__"
attendant.resourceList.70.type="__b70type__"
attendant.resourceList.71.address="__b71value__"
attendant.resourceList.71.label="__b71label__"
attendant.resourceList.71.type="__b71type__"
attendant.resourceList.72.address="__b72value__"
attendant.resourceList.72.label="__b72label__"
attendant.resourceList.72.type="__b72type__"
attendant.resourceList.73.address="__b73value__"
attendant.resourceList.73.label="__b73label__"
attendant.resourceList.73.type="__b73type__"
attendant.resourceList.74.address="__b74value__"
attendant.resourceList.74.label="__b74label__"
attendant.resourceList.74.type="__b74type__"
attendant.resourceList.75.address="__b75value__"
attendant.resourceList.75.label="__b75label__"
attendant.resourceList.75.type="__b75type__"
attendant.resourceList.76.address="__b76value__"
attendant.resourceList.76.label="__b76label__"
attendant.resourceList.76.type="__b76type__"
attendant.resourceList.77.address="__b77value__"
attendant.resourceList.77.label="__b77label__"
attendant.resourceList.77.type="__b77type__"
attendant.resourceList.78.address="__b78value__"
attendant.resourceList.78.label="__b78label__"
attendant.resourceList.78.type="__b78type__"
attendant.resourceList.79.address="__b79value__"
attendant.resourceList.79.label="__b79label__"
attendant.resourceList.79.type="__b79type__"
attendant.resourceList.80.address="__b80value__"
attendant.resourceList.80.label="__b80label__"
attendant.resourceList.80.type="__b80type__"
attendant.resourceList.81.address="__b81value__"
attendant.resourceList.81.label="__b81label__"
attendant.resourceList.81.type="__b81type__"
attendant.resourceList.82.address="__b82value__"
attendant.resourceList.82.label="__b82label__"
attendant.resourceList.82.type="__b82type__"
attendant.resourceList.83.address="__b83value__"
attendant.resourceList.83.label="__b83label__"
attendant.resourceList.83.type="__b83type__"
attendant.resourceList.84.address="__b84value__"
attendant.resourceList.84.label="__b84label__"
attendant.resourceList.84.type="__b84type__"
attendant.resourceList.85.address="__b85value__"
attendant.resourceList.85.label="__b85label__"
attendant.resourceList.85.type="__b85type__"
attendant.resourceList.86.address="__b86value__"
attendant.resourceList.86.label="__b86label__"
attendant.resourceList.86.type="__b86type__"
attendant.resourceList.87.address="__b87value__"
attendant.resourceList.87.label="__b87label__"
attendant.resourceList.87.type="__b87type__"
attendant.resourceList.88.address="__b88value__"
attendant.resourceList.88.label="__b88label__"
attendant.resourceList.88.type="__b88type__"
attendant.resourceList.89.address="__b89value__"
attendant.resourceList.89.label="__b89label__"
attendant.resourceList.89.type="__b89type__"
attendant.resourceList.90.address="__b90value__"
attendant.resourceList.90.label="__b90label__"
attendant.resourceList.90.type="__b90type__"
attendant.resourceList.91.address="__b91value__"
attendant.resourceList.91.label="__b91label__"
attendant.resourceList.91.type="__b91type__"
attendant.resourceList.92.address="__b92value__"
attendant.resourceList.92.label="__b92label__"
attendant.resourceList.92.type="__b92type__"
attendant.resourceList.93.address="__b93value__"
attendant.resourceList.93.label="__b93label__"
attendant.resourceList.93.type="__b93type__"
attendant.resourceList.94.address="__b94value__"
attendant.resourceList.94.label="__b94label__"
attendant.resourceList.94.type="__b94type__"
attendant.resourceList.95.address="__b95value__"
attendant.resourceList.95.label="__b95label__"
attendant.resourceList.95.type="__b95type__"
attendant.resourceList.96.address="__b96value__"
attendant.resourceList.96.label="__b96label__"
attendant.resourceList.96.type="__b96type__"
attendant.resourceList.97.address="__b97value__"
attendant.resourceList.97.label="__b97label__"
attendant.resourceList.97.type="__b97type__"
attendant.resourceList.98.address="__b98value__"
attendant.resourceList.98.label="__b98label__"
attendant.resourceList.98.type="__b98type__"
attendant.resourceList.99.address="__b99value__"
attendant.resourceList.99.label="__b99label__"
attendant.resourceList.99.type="__b99type__"
attendant.resourceList.100.address="__b100value__"
attendant.resourceList.100.label="__b100label__"
attendant.resourceList.100.type="__b100type__"
attendant.resourceList.101.address="__b101value__"
attendant.resourceList.101.label="__b101label__"
attendant.resourceList.101.type="__b101type__"
attendant.resourceList.102.address="__b102value__"
attendant.resourceList.102.label="__b102label__"
attendant.resourceList.102.type="__b102type__"
attendant.resourceList.103.address="__b103value__"
attendant.resourceList.103.label="__b103label__"
attendant.resourceList.103.type="__b103type__"
attendant.resourceList.104.address="__b104value__"
attendant.resourceList.104.label="__b104label__"
attendant.resourceList.104.type="__b104type__"
attendant.resourceList.105.address="__b105value__"
attendant.resourceList.105.label="__b105label__"
attendant.resourceList.105.type="__b105type__"
attendant.resourceList.106.address="__b106value__"
attendant.resourceList.106.label="__b106label__"
attendant.resourceList.106.type="__b106type__"
attendant.resourceList.107.address="__b107value__"
attendant.resourceList.107.label="__b107label__"
attendant.resourceList.107.type="__b107type__"
attendant.resourceList.108.address="__b108value__"
attendant.resourceList.108.label="__b108label__"
attendant.resourceList.108.type="__b108type__"
attendant.resourceList.109.address="__b109value__"
attendant.resourceList.109.label="__b109label__"
attendant.resourceList.109.type="__b109type__"
attendant.resourceList.110.address="__b110value__"
attendant.resourceList.110.label="__b110label__"
attendant.resourceList.110.type="__b110type__"
attendant.resourceList.111.address="__b111value__"
attendant.resourceList.111.label="__b111label__"
attendant.resourceList.111.type="__b111type__"
attendant.resourceList.112.address="__b112value__"
attendant.resourceList.112.label="__b112label__"
attendant.resourceList.112.type="__b112type__"
attendant.resourceList.113.address="__b113value__"
attendant.resourceList.113.label="__b113label__"
attendant.resourceList.113.type="__b113type__"
attendant.resourceList.114.address="__b114value__"
attendant.resourceList.114.label="__b114label__"
attendant.resourceList.114.type="__b114type__"
attendant.resourceList.115.address="__b115value__"
attendant.resourceList.115.label="__b115label__"
attendant.resourceList.115.type="__b115type__"
attendant.resourceList.116.address="__b116value__"
attendant.resourceList.116.label="__b116label__"
attendant.resourceList.116.type="__b116type__"
attendant.resourceList.117.address="__b117value__"
attendant.resourceList.117.label="__b117label__"
attendant.resourceList.117.type="__b117type__"
attendant.resourceList.118.address="__b118value__"
attendant.resourceList.118.label="__b118label__"
attendant.resourceList.118.type="__b118type__"
attendant.resourceList.119.address="__b119value__"
attendant.resourceList.119.label="__b119label__"
attendant.resourceList.119.type="__b119type__"
attendant.resourceList.120.address="__b120value__"
attendant.resourceList.120.label="__b120label__"
attendant.resourceList.120.type="__b120type__"
attendant.resourceList.121.address="__b121value__"
attendant.resourceList.121.label="__b121label__"
attendant.resourceList.121.type="__b121type__"
attendant.resourceList.122.address="__b122value__"
attendant.resourceList.122.label="__b122label__"
attendant.resourceList.122.type="__b122type__"
attendant.resourceList.123.address="__b123value__"
attendant.resourceList.123.label="__b123label__"
attendant.resourceList.123.type="__b123type__"
attendant.resourceList.124.address="__b124value__"
attendant.resourceList.124.label="__b124label__"
attendant.resourceList.124.type="__b124type__"
attendant.resourceList.125.address="__b125value__"
attendant.resourceList.125.label="__b125label__"
attendant.resourceList.125.type="__b125type__"
attendant.resourceList.126.address="__b126value__"
attendant.resourceList.126.label="__b126label__"
attendant.resourceList.126.type="__b126type__"
attendant.resourceList.127.address="__b127value__"
attendant.resourceList.127.label="__b127label__"
attendant.resourceList.127.type="__b127type__"
attendant.resourceList.128.address="__b128value__"
attendant.resourceList.128.label="__b128label__"
attendant.resourceList.128.type="__b128type__"
attendant.resourceList.129.address="__b129value__"
attendant.resourceList.129.label="__b129label__"
attendant.resourceList.129.type="__b129type__"
attendant.resourceList.130.address="__b130value__"
attendant.resourceList.130.label="__b130label__"
attendant.resourceList.130.type="__b130type__"
>
<attendant.behaviors
>
<attendant.behaviors.display
>
<attendant.behaviors.display.remoteCallerID
attendant.behaviors.display.remoteCallerID.automata="1"
attendant.behaviors.display.remoteCallerID.normal="1"
>
</attendant.behaviors.display.remoteCallerID>
<attendant.behaviors.display.spontaneousCallAppearances
attendant.behaviors.display.spontaneousCallAppearances.automata="0"
attendant.behaviors.display.spontaneousCallAppearances.normal="0"
>
</attendant.behaviors.display.spontaneousCallAppearances>
</attendant.behaviors.display>
</attendant.behaviors>
</attendant>
<lineKey
lineKey.reassignment.enabled="1"
lineKey.1.category="Line"
lineKey.1.index="1"
lineKey.2.category="BLF"
lineKey.13.category="BLF"
lineKey.14.category="BLF"
lineKey.15.category="BLF"
lineKey.16.category="BLF"
lineKey.17.category="BLF"
lineKey.18.category="BLF"
lineKey.19.category="BLF"
lineKey.20.category="BLF"
lineKey.21.category="BLF"
lineKey.22.category="BLF"
lineKey.23.category="BLF"
lineKey.24.category="BLF"
lineKey.25.category="BLF"
lineKey.26.category="BLF"
lineKey.27.category="BLF"
lineKey.28.category="BLF"
lineKey.29.category="BLF"
>
</lineKey>
</polycomConfig>