Used needle nose vice grips on the back side of the rivet to keep them from spinning when drilling it out and I got them removed without damaging the plastic. I always save stock parts. Anybody want a pair of stock teryx seats or suspension?
Anyhow, the cover plates are to keep people from using it as a grab handle while moving because your hand could be crushed in a rollover. Can you say "lawyers"? I removed them because it looks better without them, a lot better, and they are nice to grab onto while getting in and out of the cockpit. My passengers know better than to put their hands up there in case of a crash.