Use tape measure to determine proper height, width and depth of dresser's interior.
Cut a piece of plywood to size 3/4" shorter in length and width than interior dimensions, then place along bottom. This smaller sizing will allow proper wiggle room for installing plywood reinforcement.
Tip: If you don't have a circular saw to cut the plywood, the home improvement store will most likely cut it to size for you at a small charge.
Use sandpaper or sanding block to smooth out rough spots from dresser's surface. Wipe dust with a damp cloth.