Lay the 46 1/2-inch by 58 1/2-inch section on a flat surface, vertically so the 46 1/2-inches edges are at the top and bottom.
Apply wood glue to top and bottom edges of the 46 1/2-inch by 58 1/2-inch section and press one 18 3/4-inch by 46 3/4-inch onto each end. Nail into place by hammering one nail every 6-inches along each edge.
Apply wood glue to the side edges of all three plywood sections. Line one 18 3/4-inch by 60-inch section to each side, and press into place. Apply one nail every 6-inches around the three connected edges on each side of the closet.
Place the closet in standing position and measure down 18-inches on each inner side board. Line closet bar to this location and attach with 1/2-inch screws at each end.
Set the 48-inch by 60-inch section on a flat surface vertically so the 48-inch edge is closest to you. Measure in 12-inches towards the center from each corner along the right side 60-inch edge.
Attach one hinge at each 12-inch mark.
Measure up 12-inches along the left hand side from the base of the closet unit. Measure down 12-inches from the top of the unit along the left side. Attach the door to the closet by connecting door hinges at the 12-inch marks.