maybe try to pry it out after removing the dashboard panels then if you find some screws holding it in place then your're in luck... and remove the battry first, so no alarms will goe off...
um, call a locksmith. you could get in DEEP shit if someone sees you. you'll have to prove it's yours and spend a night in jail an' all that fun stuff. on the stereo, call a chop-shop. (sorry, couldn't help it)