Step 1. Mount the pulley on the motor shaft, one of the screws should be screwed on the cross section of the shaft. Screw it tightly.
Step 2. Then screw the motor on the block plate with 3 M3 x 12 screws. Insert the motor holder into the slot; you may need to use a little strength to do this. Fix the holder plate with 2 M3 x 20mm screws and M3 square nut. Be careful in case the Acrylic break down.