Remove the hopper and the upper burr and set them aside.

Use a 10mm socket to remove the nut for the lower burr. Note the threads are backwards! Rotate CLOCKWISE to loosen. You may have to jerk your wrist to break the nut free without the motor turning.

If the motor starts turning, try snapping your wrist quickly to break the nut free.

Set the acorn nut, lock washer, flat washer, and lower burr aside preserving the order.