How to downgrade back to iOS 9 if you don't like iOS 10

There are a lot of reasons as to why you want to revert back to iOS 9 after installing iOS 10. It’s not difficult to revert, but you need to do it sooner than later.
Each version of iOS is signed (approved) by Apple. When iOS updates are released, the previous version remains signed for a short period of time. Eventually, Apple stops signing the previous version, which prevents you from installing the old version.
Here’s how to revert back to iOS 9..ipsw fileFirst, you need to find