In this video tutorial, we’ll show you how easy it is to downgrade your iOS 9 device in mere minutes.
Note: This downgrade process will work until Apple stops signing iOS 8.3. To check the signing status of iOS 8.3, please visit IPSW.me/8.3. Also, you won’t be able to use your Apple Watch if you upgraded it to watchOS 2, and downgrade to iOS 8.3. watchOS 2 requires a paired iPhone running iOS 9.
Step 1: Connect your iOS device to your computer and launch iTunes
Step 2: Disable Find My iPhone via Settings → iCloud → Find My iPhone
Step 3: Place your device into DFU mode: Hold Home + Sleep button for 12 seconds, and release Sleep button while continuing to hold Home. Once you are in DFU mode, iTunes should show a notification indicating so. Click OK.
Step 4: Click Restore iPhone followed by Restore and Update
If you don’t already have the iOS 8.3 firmware on your local machine, iTunes will download it prior to updating. Otherwise, the restore process will begin and you’ll be back on iOS 8.3 in a jiffy.