408: rear suspension adjustment. What is the procedure?

[dwomby]

My car has a very slight but noticeable tilt down on the driver side. I see from Dr Pasini's site that in addition to removing and refitting the torsion bar for major adjustment, there is an adjustment screw. It's shown in the parts manual and near the foot of this page: The engine of the 409 being rebuilt in Bologna.

I can't find a description in any of the online manuals for how to do this adjustment. Can anybody describe the procedure, please?

David