Discussing the actual flashing of a phone from one carrier to another is illegal, so we don't condone discussions on the topic. If a user flashes to another carrier before joining a discussion here, it's fine. But this isn't the place for flashing instructions as the ESN/IMEI/MEID is messed with, which is the illegal part.
I'll leave the discussion open, for now, as other users have suggested solutions that do not involve messing with the ESN/MEID. Thanks!