I have a 2014 Bighorn 3875FB. One of my rear windows (~35" X 14.5") double pane broke as my unit was in storage. (Someone tried to break it). Only the exterior broke. I would like to replace it, anyone know how difficult this is or how to go about it? The window has 18 screws on the inside and I assume you unscrew, and the window separates, from the inside and outside? Any videos on how to do it would be great. Thanks in advance