Removed the old round lights that were pretty much useless:
Replaced it with a slim LED light bar that puts out a ton of light:
I noticed shortly after buying the truck that water would get into the back seat area. I checked the 3rd brake light as I know that's common but couldn't find any leaks from it. I did however find a leak in the upper drivers side corner of the rear window. The butyl tape had failed allowing water to stream right in. It took about 2 hours to remove the back seats to gain access to the bolts that hold the rear window on. It took another hour to gently loosen and break the tape the rest of the way to pop the window out.
Then came the fun part... Removing the butyl tape from the truck and the window. This took 3+ hours and I used everything I could find. In the end, WD40 seemed to break down the old tape the quickest.
After this I cleaned everything really good to get any remnant of the wd40 or googone out of there, layer in some fresh butyl tape and reattached the window. After tightening everything up, I did a test and found no leaks.