I have found this book to be invaluable in dealing with my strong willed children (and strong willed adults too): http://www.amazon.com/gp/aw/d/0770436595?pc_redir=1406967840&robot_redir=1

Basically, to be effective, you have to not take the behavior personally, make immediate consequences, make the consequences as natural as possible and be consistent, consistent, consistent.