I'm trying to change my rear signal on a Contour 1996 4 cylinder, I have opened the door that's in the trunk, and I ahve figured out how to unhook the wires, but after the wires are unplugged, the light is in some sort of a casing with a flat round white lid on it, but I can't seem to find away to remove that and I don't want to break it off accidently. Does it just pry off or does it screw off? or is there some other trick.
Help?