I want to know how to unlock an iphone 4s thats with sprint to work with tmobile. dont say its not possible because it is. When I had ios 6 my ex got it unlocked for T-Mobile. when I updated to ios 7, the phone went back to sprint, now I cant use it. I have a gpp sim. I just need a way to unlock it again on my laptop maybe? even if I gotta go ack to ios 6. (not a big fan of ios 7) please help!!