I did mine just a bit ago. Removed it, cleaned the side of the rig real well, used black butyl tape and re-installed it. I do believe that the leak is gone. The only difficult part is the 52 screws that hold it in.
Remove window valance
Remove blinds (push in the button and push the blind back)
Remove all the screws
Have someone outside and push the window out from the top to them.
Once it is out, remove the cheap foam tape, clean it well with goo gone.
Apply the butyl tape all the way around, starting at the bottom and overlapping
Spray the tape with water so when you re-install it, you can move it a little bit.
Start at the top two corners and put the screws back in, then the two outside on the bottom, the the rest of the screws in a criss-cross pattern.
Give it a day or two and recheck the screws to make sure they are tight.
On the outside use a putty knife or plastic scraper to remove the butyl that oozes out.
A note, I was able to remove the wood trim around the window by pulling out with a steady pull, and then was able to put them back in using the same staples. The wood trim just pulls out.
Let me know if you need any more info.
Skip & Patty
2013 Redwood 36RL
2015 Ram 3500 Laramie CC DRW 4x4 (Bertha)