Turn off the power to the electrical lines to be worked with at the main circuit panel. The main circuit panel is typically located in the garage or utility room.
Mount the junction box to the rafter or stud where the wires that you wish to join come together. Mount the box using the screwdriver and included screws in the kit.
Knock out a couple of the punch out holes on the side of the junction box and pull about 6 inches of each of the wires through the holes and out the top.
Strip back about 3 inches of the outer sheathing on each of the cables, using the utility knife. Be careful to not cut into the interior wires inside the cable. Cut down the side of the sheathing and peel it back and cut it away from the cable.
Strip off about 1 1/2 inches of insulation from each of the wires inside the cable. There will be three or four wires, depending on the size of cable being connected. One wire will be bare and not need stripping.
Black Wire = Hot Red Wire = Hot (if included) White Wire = Neutral Bare Wire = Ground Wire
Twist each of the same color wires together in a clockwise direction, using the pliers.
Twist on a wire nut to each wire connection. Wrap electrical tape around the wire nut to secure to the end of the wire.
Push the wire back into the junction box and mount the cover plate over the top, using the screwdriver and included screws.
Turn the power back on at the main circuit panel.