Using a pencil, measuring tape, and straightedge or ruler, mark your measurements on the sheet of plywood. If your table saw has a built-in measuring tape, you can make measurements directly on the saw. You should have two 5x5-inch pieces, which form the sides; one 4-1/2x24-inch piece, which forms the back; and one 5x24-inch piece, which forms the bottom. Following the cut list, cut your sheet of plywood down to size with a table saw. Measure and mark 25 inches on your trim piece, and cut with the table saw. Sand any rough edges and use a tack cloth to clean up the dust.