Cut, using a saw, three 4-by-8-foot plywood boards into two pieces measuring 3 feet in width by 6 feet in height, and two pieces measuring 2 feet in width by 6 feet in height. Cut an additional 4-by-8-foot piece into two boards measuring 3 feet in width by 2 feet 1 inch in length.
Screw two of the 2-by-6-foot boards into one of the 3-by-2-foot-1-inch boards to form the base and sides of the cabinet, using 1-inch screws. A half-inch of space should extend on either side of the sideboards, to allow for the back and door.
Secure the 3-by-6-foot backboard and 3-by-2-feet-1-inch board into place using 1-inch screws.
Cut, using the saw, two 1-inch thick dowels to a total length of 2 feet 11 inches each. Using 3-inch screws on both ends, screw them into the cabinet from the outside. One dowel should be approximately 1 inch from the top of the cabinet and the other should be in the middle.
Attach four hinges, spaced evenly, on the side of the remaining 3-by-6-foot board and side of the cabinet, spread evenly throughout the structure's length to form the door. With the door closed, the hinges should lay flat and appear only on the side of the cabinet.
Screw in the door handle with 1/2-inch screws.
Position the magnet halfway down the cabinet's length and screw it in place. Screw the included metal blank on the corresponding place on the door, using 1/2-inch screws. When done right, the door should shut tight against the cabinet when the two pieces meet.