i need help to downgrade my iphone 4s back to ios 5.0

downgrading the iOS is NOT supported by Apple and thus you cannot get help here.

Rocky,

What is your motivation for down grading to 5.0.0?

If it is battery problems there are several approaches that will in most cases correct that problem.

I don't know about the last posters claim that you can't discuss how to down grade your iOS on this forum but you can certainly Google for a "How to". And there are several methods I have seen posted on other forums and possible this forum.

I will say that most of the down grades are easier said than done IMHO, that said most of the "Battery Fixes" listed on this forum are much easier to implement than a down-grade of the iOS.