ES 300 replacing reverse lights

I have a 1992 ES300 which I am very happy with. My reverse lights have stopped working and I need to replace them. I am having problems getting to them though. When I take down the carpet against the inside back wall of the trunk the only electricity there seems to be for the trunck opening mechanisms, and the tail lights. On the outside of the car it looks like I could possibly pry open the outer light covers, but I don't want to do that unless I know that is the correct way to do it. Of course the owner's manual suggests I take it to the Lexus dealer, I am not interested in doing that.
Has anybody done this before? Thanks in advance for any help.

When U R in the trunk and you remove the carpet and those electrical wires R exposed, You should see around nuts , the nuts are 5/16 and the other is a lil bigger. After removing those nuts just gently pull the rear light housing away from yhe car and there R your lights... Real simple...

What he said.
10mm nuts. Metric guys, metric. =)