I can't imagine it is that much different that doing a car...
I would sand off as much paint as you possibly can, try to get down to where the factory primer is just starting to show through. Be sure to use a dual-action orbital sander so you don't wear a pattern into the plastic.
After that, it is time for wet sanding. If you have never done this... it takes a lot of patience. After you are done wet sanding, hit it with a tack cloth to get rid of any lingering dust, and then shoot the primer. Make sure to do it as lightly and evenly as possible. DO NOT spray too much on there... just enough to cover it completely.
Wet sand again with a finer grit, just to smooth everything out... then another round like above, followed with another round of wet sanding.
Then you get to repeat the above at least twice using the actual paint. You will have to add a flexing agent to the paint for the plastics, but the supply shop will be able to help you with that.
After you have wet sanded down your final coat of color. Clear coat time. Light and easy, full coverage. Let cure for a week, then hit it with the polisher.