My son signed into a friend's gamecenter account

My son signed into another kid's game center account and linked his clash of clans village to it. He now wants to get out of this, which I understand is pretty impossible to do. However, if we delete his gamecenter account and then reinstall it, would this take care of the problem? I think that this would totally delete all of his clash of clans history and that is ok with him. He just wants to disconnect with this other kid's account. Thanks.