The 4.0.2 firmware has just been released, but despite the warnings, some of you had to install this new version. We propose a method in this tutorial you can easily revert to version 4.0 or 4.0.1.
1. File configurations:
2. How to Downgrade [Mac OS X]:
3. How to Downgrade [Windows]:
4. How to Jailbreak:
- Download The firmware 4.0 or 4.0.1 on your iPhone or iPod Touch
- Download The latest version of iTunes (9.2.1)
- Download iRecovery and LibUSB power Mac, or just EasyiRecovery for Windows.
- Download EasyiRecovery v2.5 for Windows four.zero