Step 1: If you haven’t already, insert your AT&T SIM into your iPhone 4S.
Step 2: Make a drop-call to 611, which is AT&T’s customer service number. Once you’ve dropped the call, activate Airplane mode.
Step 3: Remove your AT&T SIM and replace with the T-Mobile one
Step 4: Ensure that Wi-Fi is deactivated completely by ‘forgetting’ any automatically connected networks.
Step 5: Now deactivate Airplane mode. Your device will begin searching for a signal. You will be met with the Apple splash screen followed by the familiar activation screen.
Step 6: EDGE network should automatically activate, and if all has gone well, you should see that "E" in the top-left corner of your iPhone’s screen.
Step 7: After a 20-30 second waiting period, switch your phone off, and back on again. You should once again see that Activation Required screen.
Step 8: Once you notice a signal bar, hit Use Cellular Connection
Step 9: Eject your SIM, after which you will see the activation notice for the third and final time.
Step 10: Finally, re-insert your SIM, and your device should be unlocked!
THANK 2 REDMONPIE
THANK 2 REDMONPIE
