Remove the handles or hardware from the cabinet with a screwdriver. Dampen a cloth with mineral spirits and wipe down the surface of the cabinet to remove any sticky glue or grease. Let the cabinet dry.
Remove the cabinet drawers. Turn the cabinet over so it is upside down. Place one caster in each of the four corners and mark the holes with a marker.
Remove the casters. Drill pilot holes through the marks with an 1/8-inch drill bit. Replace the casters and secure them with 1/8-inch screws. Turn the cabinet back upright and screw nuts over each screw.
Lay the cabinet on its side. Place a towel rack on the side facing you, 2 inches from the top. Mark the screw holes and drill pilot holes with the drill. Secure the rack to the cabinet with screws.
Make four marker spots on the underside of the top of the cabinet, placing one in each corner. Drill pilot holes through the marks with 1/16-inch drill bit.
Lay a cutting board over the cabinet. Secure it in place by screwing 1-inch screws through the pilot holes and into the cutting board. Replace the handles and hardware, then replace the cabinet drawers.