Stripping fender flares

[birdo]

Hi Guys,

The previous owner of my rig put on a set of vinyl/plastic fender flares to cover over 12.5 tires. They were painted to match the desert sand color of the body but whatever he used, bubbled and started to flake off. Today I have started the process of peeling off the old paint. Most of it is coming off in large strips with the help of an exacto knife and a lot of patience. The original finish is black plastic which is fine by me but I need to sand off some remaining sticky paint and would like to bring them up to a relatively smooth finish.  Would wet sanding in various grits do the job? They don't have to be perfect and I'm certainly not going to repaint them. I'm not going to remove them off the vehicle as the fasteners he used appear to be rivets or nutserts or something diabolical like that holding them on.
Thanks in advance!

[Moezer]

sand them down to your liking then respray them with black bed liner

[birdo]

Ok....the rears are done.....sanded and used truck bed liner. No sweat. Now......I really need to remove the front ones in order to do a proper job of this. However, some of the hex head bolts holding the fronts on have some sort of collar that wraps the threads and prevents the bolts from unthreading. The whole she-bang just turns. Never seen anything like this before.
What the heck would they be? I suppose the easiest thing to do is cut the heads off the bolts with a Dremel and punch them out. Any other suggestions?

[binare]

Its a nutsert if its spinning try and grab the back of it with some vice grips, if not whack the back of it with a big screw driver and hammer till it pops out

[birdo]

Ok......will give it a try......just as soon as it stops blowing a hurricane.