The Ticket

I have to replace the actual lights lens housing for my license plate on my 1994 Mustang and it appears to be held in place by a plastic screw with a phillips slot, although I have a feeling it is a pop in screw with wings that hold it in. Can anyone tell me how to remove these and replace with a new lens?? Do I just break them off cause I can't get my hands into the back of them through the trunk side to remove them if they are the sqeeze type screws. I can barely reach in to replace the bulbs from the inside of the trunk. I can get a new lens and screws if I can take the old ones out.
TIA