Rangefinder not working on Ensign Selfix autorange 1620

[Frederic75000]

Hello,

I have a nice Ensign Autorange 1620 but the rangefinder not working : when I change the distance on the lens, the split image is not moving.
Probably the lens not connected anymore to the rangefinder .
Any advice how to fix this ? How to open / taking off the lens to access tovthe rangefinder mecanism ?

Thank you for your help