1. Install the transformer. Mount the transformer on a post, stake, or the exterior of your house at least 1 foot above the ground and within 1 foot of a ground fault circuit interrupter (GFCI). If the transformer contains a photocell, make sure this location is not shielded from the sun, and also keep the transformer turned off or unplugged while installing. Apply a waterproof cover over the outlet for added weather protection.

2. Attach the cable. Check the manufacturer’s instructions to determine the size (or gauge) of the cable you need. To attach the cable to the transformer, use the wire strippers to remove about 5/8 to 3/4 inch of insulation from the cable wires. Then slide the stripped wires under the terminal screws on the bottom of the transformer. The wire should easily glide in to the designated slots at the transformer's lower end.

3. Lay the cables and arrange the light fixtures. With the first fixture in your run at least 10 feet from the transformer, determine the placement of each light. For even illumination, leave 8–10 feet between fixtures.

4. Bury the cables. Bury the cables in a 3- to 6-inch-deep trench, leaving a small amount of slack at each light juncture to connect the fixtures. Leave a small amount of cable sticking out of the soil at each fixture location.

5. Assemble the fixtures and attach the cables. Follow the manufacturer’s instructions to attach each light to a cable at each juncture. Most lights attach to a cable with a two-part connector that pierces and locks into place. Turn on the transformer to make sure the connection is successful.

6. Install the light fixtures. Attach each fixture to a ground stake. The top of each stake should be flush with the ground. Do a final check at night to make sure that you have the right amount of light and that the fixtures are upright. Then push the cable and connector under the soil about 2 inches.