1. Dismantle the old socket. Look for the word PRESS on the socket shell. Squeeze there and pull the assembly apart. Detach the wires from the socket base. Unscrew the setscrew that holds the socket to the threaded tubing; then unscrew the socket base from the threaded tubing that supports it.
2. Thread the bottom of the new shell onto the tubing and tighten the setscrew that secures it.
3. Tie an underwriter's knot in the cord to relieve strain.
4. Attach the wires to the light-socket terminals, slide on the cardboard insulator, and snap the shell together. Install a new bulb and let there be light!

Read more how-to articles here.