jerrination

I'm installing a subwoofer into my car and ran into trouble when attempting to remove the radio to splice into speaker wires. I have removed all of the trim and the two screws holding in the cover over the entire radio. I know that the cover needs to be lifted from the bottom but the cover does not pop off like it should, only the bottom half of the cover pulls away. Is there something that I am forgetting undo to remove the cover or is the cover supposed to be very difficult to remove the first time. -EDIT Found a way by just prying it off carefully hopefully will not have to take it off again