Remove the warped cabinet door from the cabinet by turning the screwdriver counterclockwise to remove the hinge screws from the back of the cabinet door. Place the cabinet door on the table with the back side facing up.
Place a clamp near each corner of the door. Tighten the clamps until the door is flat on the table. The warp in the door will disappear as the clamps force the door to lay flat on the table. The clamps will hold the door straight as you perform the repair.
Place a wood cleat diagonally across the back of the cabinet door. The cleat should be placed on the diagonal corners on the opposite side of the twist in the wood. The cleat must be short enough to fit inside of the cabinet door when it is closed.
Place a screwdriver bit in the electric drill. Tighten the bit into the drill chuck. Use the drill to place one screw into each end of the wood cleat to secure it to the back of the cabinet door.
Remove the clamps. The wood cleat should keep the cabinet door straight and warp free.