Jay 2Day
This tutorial will take a while depending on what you’ve already done, so if you’ve already jailbroken your iPhone, great! You’ve saved a lot of time.
This will also work with iPad 2.
Sideloadly!: https://sideloadly.io
6.1.3 OTA: http://3u.com/tutorial/articles/4207/downgrade-iphone-4s-ipad-2-to-ios-613-with-3utools
Filehorse: https://filehorse.com