How to Unlock the iPhone 4, 3GS, 3G Using UltraSn0w

Source : internet

These are instructions on how to unlock the iPhone 4, iPhone 3GS, and iPhone 3G for use with any GSM cellphone carrier using UltraSn0w. This will work with the iOS 4.2.1 firmware if you are on the 06.15.00baseband. Before you can follow these instructions you must have a jailbroken iPhone and you must be on the 04.26.08, 05.11.07, 05.12.01, 05.13.04, 06.15.00, or 01.59 baseband(modem firmware). To find your firmware and modem firmware(baseband) versions you can follow this tutorial.  If you are on T-Mobile remember to turn off 3G before starting... 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 button at the top left of the screen. Step Six Enter http://repo666.ultrasn0w.com/ as the source url and press the Add Source button. Step Seven Once the source has been added press the large Return to Cydia button. Step Eight Press the Done button at the top right of the screen. Step Nine Press to select repo666.ultrasn0w.com from the list of user entered sources. Step Ten Press to select ultrasn0w from the list of packages Step Eleven Press the Install button at the top right of the screen. Step Twelve Press the Confirm button at the top right of the screen. Step Thirteen After installation completes successfully press the large Restart Springboard button. Step Fourteen You should now be able to insert the SIM of your choice!  ***THANKS: A big thank you to all the members of the iPhone Dev-Team for all their hard work! It is much appreciated by all.