How do I change schools/advisors without making my advisor angry?
This is the answer to everything, but talk to your advisor.  If he is, as you say, very nice but hands off, you should talk to him.  Express your concerns, that you really feel you need a more hands-on approach and that right now you feel like you are floundering.  If you're honest and direct without blaming him, asking for help, he may change his behavior or work with you to find a better fit.  Either is good for you, but you need to talk to him.  He knows he's being hands-off, he just may not know that it is not working for you.  You need to communicate that.