Note: This is a very basic tutorial that worked for these lamps. The exact steps can vary depending on the type of lamp you have and the type of socket you’re using.
1. Buy your supplies. You can do this at a big box store, your local hardware store, or you can order supplies online. You’ll need a cord kit (or you can order wire and put your own plug on the end), a socket (I ordered one with a push through switch), and some parts to assemble the lamp. Typically the socket will screw onto a hollow piece of threaded pipe called a nipple. And you’ll need a washer and nut to hold the nipple in place and keep everything snug. If you’re using a shade with a spider attachment, you’ll need a harp. There’s a great cartoon of most of these parts here. Many of the parts — the nipple, washer, nut, and harp, for example — you should be able to salvage when you take your lamp apart. But replace anything that’s rusty or corroded.
Lamp cords come in SPT-1 or SPT-2. The designation has to do with the thickness of the insulation on the wire. For these small table lamps, I ordered SPT-1, which has thinner insulation. For this big hanging lamp, I ordered SPT-2.
2. Unplug the lamp. Very important.
3. Remove the old guts. You’ll need to unscrew the nut inside (or on the bottom of) the base. That will loosen things up, allowing you to unscrew the socket. You can clip the old wire with a scissors or pliers. As you’re disassembling the lamp, be sure to take lots of pictures. That will make it easy to figure out how to reassemble your lamp.
4. Thread the wire. Once you have the lamp base bare, push the new wire through the hole in the base (most lamps will have a place where the cord comes out). Thread the nut on the nipple, and pass the cord through the nipple. So the cord should be coming into the lamp base, and then going through the nipple.
5. Push the nipple/cord through the top of the base. Since the base of this lamp was too skinny for my hand, I used needle-nosed pliers to push the nipple through. The nut, which will be inside the base, should stop the nipple from going all the way through. If you’re using a harp, the cord should pass through the bottom part (called the saddle) before you put the socket on.
6. Thread the cord through the bottom of the socket. You can screw the bottom of socket onto the top of the nipple at this point and tighten the nut so that everything is held snugly in place. If you have a skinny lamp like mine, this might require a screwdriver, ingenuity, and lots of patience.
7. Tie the cord into a underwriter’s knot. This will keep the wire connected to the terminals even if someone tugs on the cord.
8. Wrap the cord ends around the socket terminals. Make a little hook with the bare wire, hook it over the head of the screw so that it’s wrapped over the screw’s base. Now tighten the screw to hold it in place. Remember, the wire with writing and/or ridges on the insulation goes on the silver terminal. The wire with smooth insulation — the hot one — goes on the gold terminal.
9. Place the top of the socket over the socket guts and snap everything in place.
10. Now put a bulb in. Plug it in, cross your fingers, and turn it on. Does it light up? Yes? Good job. You just rewired a lamp. No? See steps 1-9. Or consult other tutorials (I like this one). Or call a professional.