Here is a link for a thread on metro pcs that might be helpful.
http://forum.ppcgeeks.com/showthread.php?t=127995
It's just settings you have to enter, unless you put it in CAB form like the other carriers, or cook it in if you have a package. If your ESN is in their system and is working, you shouldn't need anything from them. The settings for metro pcs are in that thread I linked above.