I'm a big guy, so heres how you do it if you have tree trunks for arms.
first do the main center light. you can do all of these from the top, your gonna want a 11mm ratcheting wrench though. Then, take that light out, do the outside corner light from your knees, then do the top bolt on the inner light, however you cant reach the lower bolt, you have to stick your arm up through the scoop on the bottom, when you reach threw there, depending on how big your arm is, it will hurt like hell when you reach up to that bolt.
I just did 3 sets today, hehe. Can get them out and back in in about ~15 minutes.