How do you clean a dirty light bulb socket?

The light bulb sockets in your car are protected by lenses so they won't get as dirty as they could, but they will still accumulate dirt and grime over the years. Regular cleaning can help keep them functional for a longer period and also help you identify other problems.

How are these dirty lamp sockets cleaned?

Fuse Pulled: The mechanic will first remove the fuse for the lighting circuit. This ensures that it can work safely with the socket without electric shocks.
Cover checked: If the mechanic is cleaning the inside light bulb, he will remove the cover. This is usually easily done with a small flathead screwdriver. If he is cleaning a socket on a headlight, taillight, or brake light, he simply pulls the socket and bulb out of the assembly. If he cleans the socket on the turn signal, he can use a Phillips screwdriver to remove the cover (this varies considerably from one model to another).
Bulb removed: The mechanic will remove the bulb from the socket, being careful not to touch the bulb with bare hands.
Socket checked: The mechanic will take time to inspect the outlet. He should look for signs of burning or burns. If he sees them, you need to check the voltage in the circuit.
The socket is sprayed: The mechanic uses an electrical contact cleaner and sprays the inside of the socket.
Socket wiped clean: With a clean cloth (lint-free), the mechanic will wipe the cleaning agent from the socket. He will remove all cleaner and make sure the inside of the flare is dry and free of fibers and other debris.
Light collected: Once the cartridge is clean, the mechanic will reassemble the flashlight and replace the cartridge in the housing/lens assembly.