In the last post, we provided you links to download iTunes 9.2 beta and iOS 4 GM for iPhone and iTouch. If you are in a hurry to upgrade and jailbreak, there’s a trick that will allow you to use PwnageTool and create a custom firmware. Since the baseband of our iPhones was already upgraded, we can’t confirm 100% that it will preserve your baseband and that you can unlock. Use it at your own risk.

NOTE: this is not an official DevTeam release, so if you don’t know what you’re getting into, you better wait for an official iOS/jailbreak/unlock release.

You will need:

NOTE: The Cydia package that is currently in PwnageTool does not work for 4.0. The easiest way to get it working is to download the redsn0w jailbreak for beta 4 and extract Cydia from there and put it into your custom PwnaGetool.

How to:

1. Download the bundle and all the tools and place them on your desktop

2. First, you will need to download the custom bundle and copy it into PwnageTool. To do that, right click on and ‘Show Package Contents’ .

Browse to Contents>Resources>Firmware Bundles> and copy thecustom bundle…

3. Right click on and ‘Show Package Contents’. Browse to Contents>MacOS> . Copy Cydia.tar.gz on your desktop and extract its content.

Now you will need to copy Cydia into To do that, right click on and ‘Show Package Contents’. Browse to : Contents>Resources>CustomPackages> right click on ‘CydiaInstaller.bundle’ and ‘Show Package Contents’ > Files> and overwrite all the files with the ones you just extracted from redsn0w

4. That’s it. Now load and create your custom firmware. If you don’t know how, check this tutorial

5. Once you got the custom .ipsw, you will restore your iOS device via iTunes. Your iOS device must be jailbroken. Put the device in recovery mode and restore.

NOTE: this is NOT an official DevTeam release, and we cannot 100% confirm that it will preserve your baseband. Use it at your own risk