Best way of transferring voicemails to new pbx?

I’m upgrading a client off of their really old Trixbox to a brand new PBX with latest FreePBX and Asterisk. What is the best way of getting over their existing voicemail into the new PBX? I have already created the extensions on the new PBX. Thanks.

rsync -av [email protected]:/var/spool/asterisk/ /var/spool/asterisk/

would get voicemails and recordings also