How to Reverse iPhone to Previous Updateby Brandon Getty
Many users like to keep their iPhones up-to-date with the latest firmware, while others prefer to stay with previous versions of iOS for familiar features and navigability. ITunes does not offer a way to automatically revert to an older firmware version, so you must manually download and install it. Once you've downloaded the desired version of the iOS firmware, installing it to your iPhone is a quick and simple procedure.
Download and install the version of iOS to which you wish to revert using the links in the Resources section. Save the firmware in a memorable location on your computer. Note that many other websites also offer previous versions of the iOS firmware for download.
Connect the iPhone to your computer using the included USB data cable. If iTunes does not auto-start, open the software manually. Allow iTunes to recognize your device.
Highlight your iPhone in the list under the Devices heading in the left column. Press and hold "Alt-Shift" while clicking the "Restore" button in the main window of iTunes.
Browse to the location where you saved your iOS firmware. Select the file, which has an ".ipsw" extension, and click "Open" or "OK."
Allow the restore process to complete. Then click the "Eject" button next to the iPhone's name in the left column.
- Do not eject or attempt to use the iPhone while the firmware is being restored, as this may cause it to lock up.