Is there a way to re-assign a post to a new author if you are an admin? Currently, in 'Edit Discussion', there is no way to edit the author. Any ideas?
Don't know if there is a plugin to do this but, You could do it via phpmyadmin or sql, if you really had to do it.
look in comments and discussion tables.
I may not provide the completed solution you might desire, but I do try to provide honest suggestions to help you solve your issue.