Recently, we showed you how to download and install iOS 9 in your iPhone and iPad, but caveated at the same time that you may find a lot of lags, glitches and problems and iOS 9 is still in public beta version. You can downgrade iOS 9 to iOS 8.4 easily if you have tested iOS 9 and just want to go back where you were. Here are the steps you should follow to downgrade iOS 9 to iOS 8.4.
Downgrade iOS 9 to iOS 8.4
First, you will have to enable the recovery mode in your iPhone. In order to do so, press and hold Sleep/Wake button and slide to power off.
Now put one end of your iPhone or iPad data cable in the computer in which iTunes is installed.
Press and hold the Home button of your device, and connect the other end of the data cable with your iPhone or iPad. Keep holding until you see connect to iTunes option with red iTunes icon on your iPhone.
If you are unable to take your iPhone or iPad into the recovery mode, you can then …read more
Read more here:: How to Downgrade iOS 9 to iOS 8.4