Yes. I replaced the shower skylight on our Jayco last year, after it was broken by a falling branch in a wind storm. I purchased the replacement from adventurerrv.net.
You scrape the old sealant off the screws, then from around the edge. You must be careful, as the rubber membrane will tear, leaving a hole. You won't get all of it, and that's OK. After removing the old one, clean off the old seal as best you can. You won't get it perfect, unless there's a product out there that takes it off I don't know about. I used lacquer thinner. Put butyl tape around the edge on the bottom of the skylight, then screw into place ( I bought new stainless screws), then use self leveling sealant in a caulking gun over the screws, and around/over the skylight edge.
Look at how it was sealed originally before you start, and try to re-produce that. Good luck.
On edit; be sure the screws are not so big that they are tight in the holes, and don't over tighten. The plastic will expand/contract, and it needs room around the screws. Also, the plastic at almost every hole had small cracks going out, indicating they were over tightened at the factory. I measured mine from the top. You should be able to tell where the edges are. You could be slightly bigger, and would probably work.
Carl
2007 National RV, Sea Breeze
