I pulled the bathroom window out yesterday and cleaned the face of the Skank as well as the backside of the window of the foam rubber sealant and acrylic caulk that the PO had applied in an attempt to stop the window from leaking.
Actually, it took me about three minutes to get the window out and over an hour to clean the window frame. What a mess! I used a single side razor blade to clean the outside of the trailer skin and a putty knife on the window frame and then wiped it down with alcohol to completely remove any remnants of the caulk.
Reinstalling the window was a little tricky but the butyl tape was pretty sticky and held the window in place while I went back inside to catch the window with the frame/screws to complete the installation.
I think I used too much butyl tape because I was having trouble getting the frame to pull down against the skin of the trailer. Oh well, live and learn. If I have to re-do the job I won't be too unhappy since this was a small window and I consider this a victory as a learning experience.
Oh yah, it was way too cold at 55° to allow the butyl tape to remain pliable as well as sticky. That means it'll be a while before I can finish resealing all the other windows