I have an iPhone 4S, and I want to downgrade it from iOS 6.0.1 to iOS 5.x. How can I do this? I am willing to jailbreak the phone and erase all the data on it. I want to do this because Bluetooth AVRCP (showing song title and enabling controls like play/pause and next/previous) simply does not and cannot work with iOS 6.x and my car stereo. iOS 5.x will work.