All of it? The interior? Not sure i'd do the diffuser myself, too big a job for me.
I just went to halfords and bought a can of grey plastic primer, plastic gloss black, and some lacquer, got some 600 grade sandpaper, and masking tape.
Masked the pins and just sanded it down a little, sprayed on two coats of primer, let it dry, sprayed on two coats of gloss black letting it dry and finally two coats of lacquer and it came up a treat
never done any plastic before and didn't have any problems, so you'll be fine.
Not even sure you really need the primer, but i liked how mine came out!!
I'm sure someone will hopefully correct me if I did anything wrong, or could have done it better