These are instructions on how to unlock the iPhone with any GSM cellphone carrier using UltraSn0w.
Step One
Press to launch Cydia Installer from your SpringBoard.
Step Two
Press to select the Manage tab at the bottom of the screen.
Step Three
Press to select the large Sources button
Step Four
If the ultrasn0w repo is not present press the Edit button at the top right of the screen. Otherwise, skip to Step Nine.
Step Five
Press the Add...