Previously I posted about Unlock iPhone 3.1.3 For 3G 3GS Using Ultrasn0w, but if your baseband is 05.11.07 better use Blacksn0w from Geohotz to unlock iPhone 3.1.3 firmware for iPhone 3G and 3GS for old bootrom

Now here are the steps:

After your iPhone is jailbroken then do these steps:

• Now open Cydia -> Touch Manage -> Touch Source
• Tap on Edit > tap on Add And then type when you are prompted to enter url source: http://blackra1n.com and touch on Add Source.
• Now search for blacksn0w (once the repository added) in Cydia then install it, and this app will do the job to automatically unlock your iPhone
• Restart your iPhone your iPhone 3G or 3GS on firmware 3.1.3 is unlocked now!
• Well done!

And see you in the next post!