How to return to use version ios8 ?

Apple does not support downgrading iOS.

Since Apple does not support downgrading the iOS I suggest you start a new question that gives a good title to a specific problem. Then in the body of the thread describe the problem in detail, tell us what steps you have tried so far to correct the problem, what happened, and what error messages you received.

I have a 5s and would like to get rid of the ios9 also.

As it says in this thread, you can't.

There is no supported method to revert to an earlier version of iOS.

Did you restore your data from your backup? Or have you failed to maintain

a backup?