New Window Install , Has anyone done it ?

I put 5 windows in a cargo trailer and it was a longer project than planned but not overly complicated. Much like putting a window in a house you need to locate the studs and put a header in above and below the window. Since most TT's have wood studs it should be easier than dealing with the metal studs on a cargo trailer. Your framing will be rectangular so you will need to cut radius pieces for the corners because if you are using the clamp in style window or the screw mount window you need something solid for the corners to pull against so you can seal the window correctly. After the first window I found that making sure the trailer was perfectly level allowed me to use a level on the window frame to make sure the window was straight. I used 3M marine sealant around the frame before setting the frame in place and checked to make sure I had excess squeeze out all around with no gaps and then cleaned off the excess. I know the 3M sealant is overkill and expensive but I've used it on several boats where the joints are either under water or get a lot of wave action and it has never leaked. You are going to need to get inside the wall enough to fasten your headers securely to keep the integrity on the wall. From replacing rotten wood on campers in the past your camper will determine if that is easier from the inside or outside. On a trailer you should not have to worry about electrical wires but to be safe i would shut the power off to the trailer until I cut my hole open. If you can put a window in a house you can put a window in a trailer because for the most part they are just standard stick construction only using different materials.