Step 1 - don’t install the patch. You don’t need it for the SIP version of the Cisco phones. The patch provides SCCP connectivity, which you can’t get on this phone.
Step 2 - install the FreePBX distro ‘as is’ and connect the phone using the normal SIP phone installation process. This will either include using the Open Source EPM or (if you’re feeling adventurous) use the Chan-SCCP-B Driver and the SCCP Manager package to manage the SIP credentialed phone.