Updated to iOS 9 beta 1? Now you want to downgrade back to iOS 8.3, no worries we have you covered! To downgrade your iPhone, iPod Touch, or iPad back to a publicly released firmware, currently iOS 8.3, you’ll need to connect your device to the computer (make sure it’s in DFU mode) and iTunes will download the latest firmware available. Alternatively, IPSWHub allows anyone to manually download the latest, or any previous, firmware as well. You can get the detailed guide on how you can downgrade after the fold.
BACK TO IOS 8.3
Step 1: Head on over to IPSWHub.com to see what firmware Apple is signing at the moment.
Step 2: Check to See if your desired IPSW is being Signed (Green Check: Signed – Red X: Not Being Sugned.)
Step 3: Connect your iOS 9 beta device to your computer.
Step 4: Now you’ll need to put your device into DFU mode by holding down the power and the home button for 10 seconds. When your device turns off count 2 seconds and release the power button while still holding the home button for an additional 30 seconds.
Step 5: When iTunes launches click on your iOS device and press the restore button.
Step 6: Now iTunes will either: download the currently signed firmware, or if you have already downloaded it prior to this, iTunes will extract the software and the downgrading process will continue shortly after..
iTunes will now start to downgrade your device from iOS 9 beta 1 back to iOS 8.3. Once the process is done you can disconnect your device.