A new tool called to downgrade called “odysseusOTA” is made available to switch to from iOS 8 to iOS 6.1.3 . First and foremost, you should know that this tool is only compatible with the iPhone 4S and the iPad 2.
If you find that iOS 8 slows your device, you now have the possibility of returning to iOS 6.1.3 that many users consider more stable and faster on these two devices. To enjoy it, have on hand a Mac, follow the video tutorial to the letter on the steps in the Terminal, and of course your device is running iOS 8 with the OpenSSH package installed.
Although iOS 6.1.3 no longer available on iTunes, Apple still sign OTA (Over The Air) – which will facilitate your task to return to this firmware. Be aware that this tool downgrade concerns only the iPhone 4S and iPad 2, no other device is compatible.
Download odysseusOTA from here. And follow the tutorial video. You need to jailbroken your iOS 8 device or you will not have access to OpenSSH.