These are instructions on how to downgrade from the iOS 7 Beta to iOS 6. You will only be able to downgrade to the latest iOS 6 release (Currently that is 6.1.4 for iPhone 5, 6.1.3 for iPhone 4S). You cannot use your saved SHSH blobs on any A5+ device — they are (currently) useless.
Apple states that “Devices updated to iOS beta can not be restored to earlier versions of iOS. Registered development devices will be able to upgrade to future beta releases and the final iOS software.” However, we were able to successfully downgrade by following these steps.
Before attempting any downgrade, please be sure to backup all of your information.
Download the latest iOS 6 firmware for your device from here.
Launch iTunes from your dock.
Place your device into DFU Mode by following these steps. Here is a full tutorial on how to put your iPhone into DFU mode if you need additional help.
Once you receive a message telling you that your iPhone is in recovery mode, press OK then select your iPhone from the list of devices in iTunes.
iTunes will go through the process of the restore/downgrade and after about 10-15 minutes, your device will be freshly restored to iOS 6.