Also to unlock your iPhone firmware 3.1.2, first you will need to jailbreak it. Please follow our mentioned posts for jailbreaking iPhone 3G and 3GS on Windows and MAC.
Steps To Unlock iPhone 3.1.2 Firmware Via Ultrasnow
- Download and install iTunes 9
- Make backup of your iPhone's data through iTunes. Click on the name of your iPhone on the iTunes sidebar on the left and click backup button
- Make sure you have jailbreaked your iPhone on firmware 3.1.2.
- Once you are done with the above procedure you can unlock your jailbroken iPhone using ultrasnow 0.9
- Start "Cydia" on your iPhone.
- Touch on "Manage" tab on the bottom.
- Now touch on "Sources" as seen in the screenshot below:
- Touch on "Edit" and then on "Add". You will be prompted to enter a url source as seen in the screenshot below. Type "http://repo666.ultrasn0w.com" and touch on "Add Source"
- Cydia will now automatically update your sources by following a series of automated steps
- After installation is completed. Search for "ultrasnow" in Cydia and install this application (T-Mobile users should disable 3G before installing ultrasnow). This app will automatically unlock your iPhone so that you can use it with any carrier.