First find a clean, well-ventilated, area to do you painting. You can wipe the rings down with a pre-solvent or simply a clean rag to be sure there is no residue that would cause a bad reaction with the paint.
We hang the rings when we paint them in order to get paint all the way around the sides. The sides of the PCB are more porous and will suck up the paint fairly quickly.
Start by spraying a coat of paint on the ring, in this case we are using a satin black finish that does not require a primer. If your paint requires a primer you would spray that now.
Once the ring is completely and evenly covered you can move on the the others.
After about 10 min you can spray on another coat of paint.
Now you will need to give the rings a while to dry, this would be a good time to start removing the headlights from the car.
Once the rings are completely dry get a sheet of 1000 grit automotive grade paper.
Put the paper on a flat surface with the sanding side up and begin to rub the ring with light pressure in "figure 8" motions.
After about 20 seconds of rubbing you should have this:
Now you are ready for clearcoat and installation!