Mode Dial on back of z650 camera not turning?

The large dial on the back of my z650 no longer turns to make different camera settings. The button is the center still works. The dial does look "dirty" near the center ring. On your teardown, I see that 6 screws will remove the case. Would this allow access to the dial for cleaning, without have to disturb any of the other parts? Dirt may have also gotten inside the mechanism for this dial. A novice may be better to leave it alone than risk not being able to put it back together. Lucky the dial is stuck in auto mode, and still works perfectly.