My brother is 19 years old, smart, immature and a "bad boy"

There are the "nice guys" and the "bad boys".

My brother is 19, going to university to study engineering and he bully's people sometimes. He is a good person but he has a flawed character that he enjoys bullying, presumably because he is insecure. He needs to stop this, start treating himself with respect, stop hitting younger guys on nights out, stop behaving like a school boy. Stop putting people down. Now, this is an occasional character flaw of the fact that he is in a negative secondary/high school environment (or has been for the last 8 years).

He needs to first realise that he behaves like this, realise why it is disrespectful to himself and lowers his social value. He also needs to build confidence and character.

Therefore --- I am looking for a book that will show him how to change from a bad boy to a man.