I own a few pairs of Jamo CS5 (active speakers, as best I can tell, based on the Model 28, just with built-in power amplifiers). Seeing as how they're going on 20 years old, the volume potentiometers are getting scratchy, and so could use a good cleaning with contact spray. But I am unsure how to get them open without damage -- there are a few screws on the front, as well as on the back, but after removing them, nothing seems willing to come off. I thought I'd ask here if anyone has any tips, before I go breaking something. Thanks!!!