How to downgrade to ios 6.1.2 on iphone 5?

I have shsh blobs and now I want to know how to downgrade.

Wow! This Question is great, I also waiting for best answer

Heres a link for you http://www.redmondpie.com/how-to-downgrade-ios-7-to-ios-6-6.1.3-6.1.2-tutorial/ Hope this helps!

You can only downgrade if you have previously preserved it baseband. If you don't know what that is well. If don't remember saving any file when you were in 6.1.2 then you are stucked in this version.

Its not possible on iPhone 5 even with blobs, only on iPhone 4.