If you don't care about a perfect job...
1. Wet sand with 400 grit, cross sanding on the spots where the paint has left an edge (this will even out the jagged line left by paint flaking off)
2. There are companies on the internet that will colormatch your paint code and custom fill an aerosol can for you, so check them out. Or go to wal-mart and get some high gloss black.
3. Just make sure to use even strokes about 8 inches from the car and about 24 inches in length. This method should produce a relatively even coat of paint, and then you can machine buff and hand polish it to a high gloss.