Downgrade iOS 9 to iOS 8.4

Step 1: Turn Off + Connect to Mac / PC via USB

Step 2: Launch last version iTunes

Step 3: Enable device into DFU mode:

a) Turn off + Hold down the Power + Home buttons together for
10 seconds

b) Continue holding Home button
until iTunes notifies you of a device enable “recovery mode”.

Step 3: Restore via iOS 8.4 (last version iOS 8.X):

a) Restore from the iOS 8.4 backup.

b) Restore to iOS 8.4 IPSW by Option-Clicking the “Restore” button.

Step 4: Device will reboot when finished!!!

Ok. Don’t forget: Apple will closed all downgrade features only after official iOS 9 release date in September. You can test new features in iOS 9 before september. It’s very nice, because iOS 9 beta 1 will be released 8-th June. :)))