How To: Downgrade your iPhone firmware to an earlier version

If you want to jailbreak your iPhone or iPod Touch, it might be necessary to first downgrade your firmware so the jailbreak will work properly. This tutorial shows you how to downgrade from 2.2.1 to 2.2 using quickpwn. Then access your iPhone through iTunes and use the Restore function to restore your device to an earlier version of the firmware.