Your original sockets can be looking pretty bad, and a simple clean up may not be the answer, since the socket inserts are usually worn, sloppy and corroded.
After removing the old socket from the housing you can clean and paint it. Sometimes a slight enlargement of the socket hole to 3/4" is necessary. Then you are ready to install the billet socket with either a single or a double filament depending on your needs.
Tighten the nut and everything is ready to go!
Don't forget to use dielectric grease on the base of the bulbs!
The outcome is years of trouble-free lights with a quality socket that will stay in shape!