How should I tell my parents I want to drop out of college?

You should talk to the college adviser or campus support first to find a better way and really find out why you do not want an education. Sit down with your parents and explain why you don't feel like pursing this. Is it the school, studies, friends, etc. I don't think they will "cut you off", but on the other hand if you're not in school they will probably expect you to get a full time job and support yourself. Did you just start or are you near the end? All this will factor in.