How can I downgrade my iPhone from firmware 1.1.1 to 1.0.2 or earlier?
Since Apple released iPhone firmware update 1.1.1, there has been a lot of griping and complaining about Apple “re-locking” the iPhone. Users with SIM unlocked iPhones have had their phones bricked, while those who installed third party enhancements and applications on their iPhone have had these applications rendered useless.