These are instructions on how to software unlock the iPhone 3GS with OS 3.1 for use with any GSM cell phone carrier. Before you can follow these instructions you must have a jailbroken iPhone if you haven’t jailbreaked your iPhone 3GS then follow our Guide to How to Jailbreak iPhone 3GS on OS 3.1 Pwnage Tool (Mac) or How to Jailbreak iPhone 3GS 3.1 on Windows. For unlocking your iPhone UltraSn0w, a soft unlock payload from iPhone Dev Team is used. UltraSn0w is a small daemon that is launched on boot. It injects the payload at boot and also whenever there is a baseband reset. You won’t notice anything about it other than that your third-party sim now works. Once you have a Jailbreaked iPhone then you can use these easy steps to Unlock your iPhone.
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 : Press the Edit button at the top right of the screen.
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 http://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 Return to Cydia button.
Step Fourteen : Now press the Home button then power off and power on the iPhone. You do this by holding down the power button for 3 seconds then moving the power slider that appears to the right. Press the power button again to turn on the phone.
Step Fifteen : You should now be able to insert the SIM of your choice!