There are 4 plastic rivets holding the housings in if they haven't been removed and replaced with screws. The easiest way to get to the 2 on the top, is loosen the 8 nuts, 4 each side, that hold the brackets to the back trunk panel, If you have bumper guards, you will have to loosen the 4 nuts, 2 each side, that attach to the frame. The 4 lower rivets can be had from under the bumper. They are push in type about 1 inch long with soft threads like a screw and you have to pry them out. If your bumper filler is off, you should have access and won't have to loosen bumper. The 8 screws only hold the lense in and don't forget to remove the metal bar attached to the top center of the bumper behind the license plate door. If you don't, you will break the lower inside corners of the housings.