� Turn the rotor plate (#632) in the direction of the arrow so that clearance (0.5mm � 1mm) can be left at "B" part. � Pinch the self-made tool #632 into the clearance.� � By using the barrier-releasing self-made tool, open the barrier unit (#B631). � Hold the barrier unit (#B631) with the mark upwards, and hook it on two parts of the 1st lens-G tube to assemble them.