How to downgrade iphone 4s ios 9.0.2 to ios 8.4?

How to downgrade iphone 4s ios 9.0.2 to ios 8.4? - 1

I don't think you can downgrade something.

Can't

No way in hell that Apple will let you do that.

Downgrading is becoming a thing of the past. The last device that's possible to downgrade with SHSH Blobs is the iPhone 4 and I believe the iPad 2(I might be wrong) and the iPod touch 4.

Can't.

I don't think its possible but you can try factory reset you iphone, also do backup before doing this. As a smart Phone user, Also install Leo Privacy Guard. It will help you to hide and secure your personal data such as images and videos. It can also lock applications.