First you need to downgrade from 1.1.2 to 1.1.1.
Download the 1.1.1 firmware file here – iPod / iPhone
Connect your iPhone/iPod Touch to your computer and open iTunes
Hold down the ‘Shift/Option’ key and click the ‘check for updates’ button in iTunes
This will open a dialog box. . .browse to and select the ipsw file and let iTunes downgrade your iPhone/iPod Touch
Once this has finished you will be using firmware version 1.1.1 and you can continue the steps below.
To put 3rd party applications on your iPhone or iPod Touch follow the steps below.
1. Visit www.jailbreakme.com on your Safari browser(on the iPhone/iPod Touch)
2. Scroll down to the bottom and click the ‘Install AppSnapp‘ link
3. Once it finishes you should be able to use Installer.app(should see the icon)
From here you have two choices.
Nothing. Go ahead and install the apps you want.
Continue. Update to 1.1.2(and jailbreak again).
1. Go into Installer.app, select ‘all packages’ and install ‘Oktoprep’
2. Plug the iPhone/iPod Touch to the computer and open iTunes
3. Download the 1.1.2 firmware here – iPod / iPhone
4. Hold Shift/Option and click ‘(check for updates’ button in iTunes(NOT restore) and update your iPhone/iPod Touch to 1.1.2
5. While it is updating download THIS archive and extract it on your computer
6. On Windows make sure you have Java installed then double click on windows.bat, on a Mac, double click on jailbreak.jar
7. Do what it says and you’re finished!!!
After the 2nd reboot of your iPhone/iPod Touch you will see the Installer.app and/or SSH.app icons. You may see your iPhone/iPod Touch ‘lock’ during this jailbreak process. . .just go ahead and ’slide to unlock’.