In following you can find step-by-step guide to learn how can you unlock iPhone 4, and iPhone 3GS over jailbroken iOS 5.1 using UltraSn0w Fixer.
How to Unlock iPhone 4, 3GS on iOS 5.1
Requirement
Jailbreak your iPhone over iOS 5.1 using latest RedSn0w or Sn0wBreeze
Step-1
Tap on “Cydia” from Springboard, and then tap “Manage” tab
Step-2
Tap “Sources” > “Edit” > and “Add” button and type the following source in field and tap “Add Source” button
http://repo.iparelhos.com
Step-3
Tap “Search” tab and search for UltraSn0w Fixer, and when found tap on that to install
Step-4
Now search for “UltraSn0w” through “Search” tab and install it and reboot
Done! You have successfully unlocked iPhone 4, 3GS over jailbroken iOS 5.1 with UltraSn0w Fixer.
See also:
Jailbreak iPhone 4, iPhone 3GS over iOS 5.1 with RedSn0w
Jailbreak iPhone 4, iPhone 3GS over iOS 5.1 with Sn0wBreeze