Groutaone figured out probably the best way to do it here. I've had extremely good luck with this method when trying it on seeerrriioouusslllyyyyy scaled plastic.



But like Greek said, 0000 steel wool will work but the upside to the blade scraping is that it completely levels the plastic. I tried using steel wool only on a Tri-Z front fender and I ended up with little 'tumor' spots where the plastic wasn't as completely dead in one spot as another.