Please help! I need advice to help a friend with a problem at school?

Inform your school's Dean of Students, principal, or guidance counselor. This is too much for you to handle on your own even with the best intentions. If something were to happen you would regret your decision to tackle this yourself. It sounds as if Scott needs more than just one person in his corner. Someone with training in psychological issues and adolescent behavioral therapy needs to get involved. Trying to be a good person morally is an admirable trait but you have to step back from being the hero sometimes and let others take control.