Bill,
Not too difficult to install, just takes a little finessing. Can't remember what I used, either a thin bead of weatherstrip adhesive or RTV (I'm thinking RTV) on the tailight housings, then put the gaskets on the housings. I think there's a couple of pins that align the gaskets. I moved the gaskets around until they just fit inside the edge, or as close as I could get, and let the RTV set up. Then set the housings into the tail panel. I put 3M strip caulk on the studs inside, then put the nuts on. Just snug them down. The gasket will compress to the body overnight. You'll need to re-snug the nuts a couple more times until gaskets stop compressing. The center emblem can go on last... Be careful, if there are any gaps you risk breaking a tab off. I had to use some thin washers between the emblem and body to get the rear emblem where it looked good and didn't put stress on the tabs. Easy, just a couple of hours... Lol!
Hope that helps!
Mark