There is a trim piece that is just held in by some spring clips that just pop out. Start by grabbing the seam across the top on one side and just pull outward. Once you get this pulled out then grab the cargo light switch from the backside of this casing, and squeeze and it should push out the front. the wiring harness clip should have button on top to disconnect the harness. do not worry with the white parts of this clip. that is just to get the wires out. If you need to do that...well i am out of answers. This should get you started. Good Luck!