I got a high temp engine paint from a spray can, sprayed it into the lid (VERY FAR AWAY FROM THE CAR...DON'T WANT OVERSPRAY), then used a 1/2" brush to apply.
Lift car
Take the wheels off
Clean the brakes first with a break cleaner spray, use a wire brush if really bad.
Let dry
Brush on paint as stated above...some say its best to remove the caliper...but I didn't. Use a Q-Tip to get in the hard to reach places. Just be careful if you're not taking the brakes off.
Let dry before putting the wheels back on...couple hours at least.