Since I'm the only person I know of that's cut up a World Cab to modify it, and since I take lots of photos, I checked to see if I have a photo of that section of the top. Unfortunately, since I scrapped the area around that joint because it wasn't part of my final design, I don't have any photos of the joint, but what I recall is that the two roof panels are spot welded together under that hat section. There isn't really a way to get them apart that's guaranteed to be non-destructive; I'd recommend a spot weld cutter but I think the welds are so close to the roof that you won't be able to get the spot weld cutter 90 degrees to the weld you need to drill. The World Cab I cut up was a CJ-7 version, but it's identical in design to the CJ-8 version so I assume the joints are spot welded just like mine. Good luck.