See PDF attached to adjust sensor group 

A) remove the temple support shaft

B) open the sensor holder and remove the plastic lower cover (IF YOU CAN NOT OPEN THE DOOR  GO TO  POINT D)

C) loosen the 2 screws and approach the magnet to the door sensor then fix the 2 screws

D) remove  the plastic sensors cover

E) if present remove the relevant screw of the fixing metal rod  ( In the case of dual sensor must be removed if present). This screwblocks the rotation of the door sensor and puts only for PAN ONLY.                       

F) check the right position of the movement group : position the flag in the sensor ( 1)  

G) check well that the movement group keeps the right position ( open and closed ) .

H) Mount the group in the same position and check that the cables (2) and the  movement group are in the right position ( Pano and Ceph ) , mount the plastic lower cover and the temple support shaft.