Don't use the wet sand paper method; just use rubbing compound. You get like a cotton terry cloth (maybe one of the wife's wash cloths

)and you wet it down and ring it out so that it's damp. Put some rubbing compound on the cloth and start rubbing the paint.
You're gonna see some paint come off onto the damp towel; that's perfectly normal because you're removing the rough paint that had too much solids. When your towel gets clogged up with paint, switch to a new part of the towel. Follow up with a dry towel and buff it out.
I'm not exactly sure on the grit, but I've used the No. 7 brand and it's worked pretty good. I think No. 7 comes in one grit. Maybe one of the other dudes will know exactly what grit to use.