get your self some sand paper....300 should be all you need really. Sand off everything that is peeling and get it all smooth. Wetsand it if you'd like for a better final product (just a spray bottle with soapy water is all you need). Get it ALL smooth and then clean is off with some soapy water and rinse thoroughly. Let it dry. Tack it off (by tack I mean take a rag with a minimal amount of mineral spirits and just get the dust, oil, and any remaining contaminants off). Tape off what you don't want painted....don't be afraid to get crazy with the masking. Better to have ZERO overspray and alot of newspaper left over. Then spray it will semi-gloss black or flat....your preference. Light even coast. 2-3 should be good.
TIP: Put the spray paint in a bucket of hot water before painting. It makes the paint thinner and raises the car pressure for a finer coat. Less likely to encounter runs and it goes on more even. I learned this when I flat blacked a 91 Eagle Talon.
I'm going to be doing my rear insert from scratch with a rattle can. I might be a tech article outta it....