OK, if you're going to try it, I'll try to highlight what I did.
1. Remove tail lights.
2. Mask off everything you don't want painted. I would recommend painting the area around the keyhole on the right light. I masked it off, thinking the paint would scratch if I missed with my key, but I always use the remote anyway, so I wish I had painted it now. You can see it on the picture.
3. The moment of truth... lightly sand the unmasked areas. I used a fine steel wool, it seemed to work well.
4. Clean off any debris left by your sanding.
5. Apply a few THIN coats of primer (I'm assuming you're using spray paint of some kind). Let each coat dry before you do the next.
6. Lightly sand the primer, I used the steel wool again. Clean up any dust again.
7. Apply a several THIN coats of paint. Again, make sure to let each coat dry before applying the next.
8. Now, I think the clearcoat stuff I had told me to sand again, I don't recall if I did or not. I'm thinking I did though.
9. Apply a few coats of clearcoat. This may be where I screwed up, maybe I didn't put enough on, I don't know. You at least need enough so that you don't scratch the colored paint underneath.
10. Remove the masking tape. Be a bit careful here so that you don't lift up any paint that you want to stay.
11. I then waxed the painted part of the light a few times to try to get it to shine more, but it didn't really help.
Like I said, I don't think mine look bad (from a distance), but up close, they certainly don't look perfect either... I suppose you can judge from the picture.
Picture