Use this easy guide to downgrade your iPhone:

http://hackint0sh.org/forum/showthread.php?t=18353

enjoy

NO!!! DON'T DO IT!!!
A follow up is being typed up.

If you have a 4.6 bootloader, this won't work for you even if you downgrade the BB.
On the other hand, since anysim 1.2.1u is out and works, I suggest anyone who has a phone with 3.9 bootloader to upgrade to 1.1.2, downgrade to 1.1.1 and then use anysim 1.2.1u to unlock. After the unlock, install OKtoprep, and UPGRADE to 1.1.2 SAFELY. Finally, jailbreak with Touchfree.

Did you even read the guide? It states at the bottom that it will not work for OTB iPhones with 1.1.2 only for those who made the mistake of upgrading to 1.1.2 and want to go back to 1.1.1

Originally Posted by chadpriddle

Did you even read the guide? It states at the bottom that it will not work for OTB iPhones with 1.1.2 only for those who made the mistake of upgrading to 1.1.2 and want to go back to 1.1.1

yeah at the bottom...it would probably be better if those details were presented at the beginning of the guide.

Originally Posted by Jedi7

yeah at the bottom...it would probably be better if those details were presented at the beginning of the guide.

ya, i know. but the fact is...if you think there is an unlock guide out for an OTB 1.1.2 then you probably shouldn't even be hacking your iphone. And the thread title says how to downgrade to 1.1.1

c'mon people, search and read before you post!

chadpriddle's guide worked for me.

week 28 iphone
itune updated me to 1.1.2, BB4.2.13_G
following his guide i sucessfully rolled back to 1.1.1, BB4.1.13_G, activated and jail broke.

i am a happy camper