Remove any decorative surface of the lighting to expose the mounting holes underneath. Plug the lighting into an available outlet if the lights operate with a plug. Position the lights underneath the cabinet to determine what locations cast the best light on the surfaces below. Position the lights without having them on if they need to be hardwired into the electrical system.
Mark the location of the light screw holes at the desired locations. Mark the places in the cabinet surfaces where the electrical cord of the light will need to travel through to remain out of sight yet reach the electrical outlet or hardwiring wall access point. Drill out these holes for the light screws and for the electrical cord pathway.
Unplug the electrical cord from the outlet and disconnect the cord from the light if possible. Pass the electrical cord through the holes along its pathway and reconnect the cord with the light.
Drill the light in place by screwing 1/2-inch wood screws through each mounting hole and into the cabinet holes. Secure the plastic light covers over the lights once more.
Fasten the electrical cord to the cabinet interior surfaces by securing it with plastic insulated electrical staples every six inches, keeping the staples evenly spaced on either side of the cord. You attach them with either a hammer or screwdriver, depending on the type. Plug the cord into the outlet or have an electrician hardwire it into the system unless previous electrical experience allows you to do so safely.