You'd better first obtain a bachelar degree through some self-taught or evening programs, because a bachelar degree is required almost by all top schools.
Of course, in some special circumstance, applicants without a bachelar degree are admitted. But the number is too small, and such applicants must have very very strong background and truly outstanding marketing skills.
If you can't wait until you get a bachelar degree, you need first contact the adcoms to inquire about your "get-in" possibilities. You can only apply those shcools who give you positive replies.