I just used wet and dry sand paper to rub it off the inside, I was going to test some paint stripper on the broken wing to see if it harmed the plastic or not but I had none. So anyway sandpaper isn't the best because it scratched the plastic BUT if you use very fine paper like 2000 grit in the end it's pretty good. Better than the silly paint they come with. Start with 600 grit then 800 then 1500? then 2000. Something like that.
I really really really reallllllllly think they should come with a clear body, then with the money they save on paint they can put bearings in the kit