Hey guys!

I recently got a Blackberry 8800 from a friend that is on the T-Mobile network, and i'm trying to flash it over to AT&T. I already have the phone unlocked, and so far having major trouble trying to find out how to go about doing this through standard searching.

(unable to search the forums, as I keep getting a "403 Forbidden" error for some reason)

Is it possible to flash the firmware on this phone from one network to the other? And how would I go about doing it?

Any help would be much appreciated!