Hi!
You want to replace your FreePBX box with them?
If so, that’s quite naughty of you… 
If you want to keep FreePBX in the loop I would do what @dicko suggested here:
However, you might be able to do it directly on your provider’s site and remove your current PBX entirely from the loop…
(I know some providers allow this, notably VoIP.ms…)
Good luck and have a nice day!
Nick
PS: Let’s hope things don’t work out and you stay with FreePBX…