Orient the laser unit so that the locking pin is at the level of the appropriate (round) hole in the PNP interface disc or collimator rotation unit.Insert the mushroom feet of the laser unit into the slotted holes of the PNP interface disc or collimator rotation unit and turn the laser unit counterclockwise until it stops (7.5 [°]).Lock the laser unit by pressing the locking pin all the way down.Pick up the dummy weight and at the same time pull out the locking pinPlace the dummy weight as far as possible over the cone of the laser unit and release the locking pins.