I'm in the process of removing my roof rack rails so I can repaint them. I hit a little snag when I realized that the last owner was a nutcase and went to some length to prevent the removal of just one of the roof rails.
The roof rack uses torx screws to hold it in place. The last owner filled in the torx head with a metal plug and bonded it in place, so its essentially a rivet now. The plug was completely flush.
I took a Dremel and attempted to cut a slot in it so I could remove it with a flat screw driver. That failed because the slot stripped, and I can't remove any more material before I start cutting the roof rack itself.
So what are my options now? Drill out and increase the screw size or try a screw extractor?
If worse come to worse, what size drill bit should I get to drill out the screw?
Removing everything from the roof is a really simple job. Each roof rail has 4 or 5 torx screws holding it to the roof, the outer 2 torx screws also hold down a plastic cap preventing you from sliding the cross bars off. Once you remove the rail caps you can slide the cross bars off, it makes it easier to lift the roof rails (the ones that run the length of the roof) off. If the last owner hadn't put a hardened plug in one of the screws, I could remove everything off the roof in 15 minutes.
From there you can go about disassembling the roof components. The crossbars and roof rails have a rubber insert to protect the paint when they are fitted to the roof, you can just slide it out. You need a Philips screwdriver to separate the plastic part of the crossbar from the aluminum part (I'm only painting aluminum so I separate the plastic parts). I keep everything labeled in plastic bags, but I don't think there are any parts that could be mixed up.
You could try a chisel and hammer to loosen the bolt, that will work even with the slot you cut being stripped. If you end up having to drill it, I'd use a left handed drill bit. Sometimes that alone will back it out as well.