Step 1: Unscrew the screws that fix the upper cover of the motor, and open the motor cover.
Step 2: Remove the communication cable, motor cable and power AC cable connected to the controller. Remove the screws that secure the controller, and then take off the lower control.
Step 3: Install the screw on the new lower control, and then plug in the communication cable and the AC cable of the power switch and the motor cable.
Step 4: Put on the motor cover and tighten the screws that fix the motor cover.