2,000 grit sandpaper and a lot of primer and time. I actually had to do that twice because I didn't know that Krylon gray primer traps moisture and will wrinkle topcoats if you try to wetsand it. That was a hard lesson to learn.
Thanks for all the compliments guys! I've started work on Chell's heelsprings as well. These need to be done in time for DragonCon by the end of the month.