First, check to see if the version you want to downgrade to is still being signed. Google should do the trick or else idownloadblog.com always posts when an ios version has stopped being signed. Second, go to ipsw.me and download the version you want to downgrade to and download it. Idownloadblog.com also has a downloads page where you can find ios versions. Third, go to your downloads folder and open the file you just downloaded. It should open in itunes. If not, use open in. Fourth, use itunes to install the ios version like normal Notes: You have to either set up your device as new or restore from an itunes or icloud backup you made on the version you are downgrading to. In other words, you can't restore from a backup made on a higher version then your device is running.