Cut two 3- by 2-foot pieces of plywood. Sand the edges to remove splinters and burrs. Cut two 2- by 2-foot pieces of plywood. Sand these also.
Place the pieces together to form a box, open on the top and bottom, with the shorter pieces overlapping the ends of the longer pieces. Screw the pieces together where they overlap, using wood screws spaced every 4 inches.
Cut a 2-foot by 3-foot, 1 inch piece of plywood. Sand as necessary. Place this on top of the open box and screw on with wood screws every 4 inches. Turn the box over.
Cut a piece of plywood that measures 2 feet by 3 feet, 4 inches. Place a 20-inch piece of 1- by 4-inch board on each end of the plywood sheet, 3 inches in from the short edges. Screw this onto the board.
Flip the panel over and place it on top of the bin, with the 1- by 4-inch boards facing in. The boards will ensure that the lid doesn't slip off.