Measure the area where the lights will be installed, and mark the edge. Using a speed square, continue the line under the shelf. Mark a line along the length of the shelf at the bottom so all of the lights will line up.
Drill holes for the electrical cords using a paddle bit.
Attach the first light to the bottom of the shelf, and continue installing the remainder of lights.
Feed the cord up through the hole made earlier, and attach the small transformer to the underside of the shelf. Connect the individual lights to the cord.
Organize the wires under the shelf using wire staples.
Install the switch and the plug.
Spackle up any exposed nail holes, and then paint over it.
Add aluminum trim to the edges of the shelves to give them a finished look.
Attach the door handle to the closet door, and set the closet shelf and rod into place. Install chrome cover plates to all electrical outlets.