It's best to be open and honest. Anticipate the person becoming upset and have a plan in mind of whether you or him would move out. Also, if you are afraid of his reaction, let a friend know ahead of time when you are going to break up.
Well I think you need to cut all ties with them, it will be easier on both of you if you do not have to see each other. Also get all the bills out of his name and yours only.
