Step-by-step tutorial: How to Unlock Your iPhone 4S, iPhone 4, iPhone 3GS Using SAM v0.1.16 [iOS 5.0, 5.0.1, 5.1]
UPDATE: Apple is blocking SAM unlock
Tap to launch Cydia from your SpringBoard.
Make sure your Method is set to Auto Detect and tap Utilities.
Note: If Auto-Detect doesn't work you can change Method to By Country and Carrier and select the phone's ORIGINAL carrier manually.
Press the Attempt Activation button. If you don't see Attempt Activation then select De-Activate iPhone and the Attempt Activation button should appear.
A popup will appear letting you know that "this may take a while".
Eventually your iPhone will respring and after searching for a bit your new network will be detected!
You should now backup your iPhone unlock ticket in case this method is ever blocked.
If push notifications stop after this process, you can restore then with the Clear Push utility in SAM, followed by connecting to iTunes.
Your phone will work normally with your SIM card and that SIM card ONLY since we have tricked iTunes to think that ICCID is one of the intended carrier's. The phone can be rebooted and connected to iTunes freely without losing the "unlock", at least for now.
A big thanks to Loktar_Sun and Laforet for their contributions!
Follow us on