[s-cars] How to Synchronize Sunroof for URS6

[weski at verizon.net]

Patient is a 95 S6 with 240k miles on the clock.  The sunroof has been 
not operating properly and at times won't close (the dial is set to 
close and the sunroof stops part way closed).  Some times I've been able 
to use the key to lock the doors and close the sunroof but that doesn't 
work any more.  I've had to resort to manually cranking the sunroof closed.

My question is, do I just need a new potentiometer?  ETKA #895-959-613?  
There're not cheap so I figured I'd enlist the wisdom that is the S-Car 
list.  If I do replace the potentiometer, what procedure would I have to 
do before the sunroof position would be in sync with the control position?

TIA,

Paul
95 S6 hoping to use the sunroof again before the great weather is gone