Are you talking bout the interior handrails or exterior. You say Mk 2 so that would be newer than 1987 with T cockpit. The exterior on mine '88 are screwed up through the cabin top into the rail above. I drilled out the screw holes and installed
threaded wood inserts so that I didn't need to worry about the wood stripping out. If you are talking about the interior handrails, i have never removed them and do not see a reason to unless they are broken. If you need to remove them, there is probably a wood plug in the center of each support. Drill a 1/8" hole into the center of the plug until the bit hits the screw below. Then take a drywall screw and thread it into the hole. It will hit the screw and then the threads will pull the plug out of the hole.