How to clean sliding power switch on HP21 Woodstock

[jupiters_spot]

Perhaps I posted prematurely. Upon further inspection, if you look from the display area towards the keyboard you can see the mechanics of the switch just beyond the edge of the PCB. It appears the switch is not enclosed, but rather that the slider and metal spring are held in place over the contacts on the PCB. Because that switch is adjacent to the PCB edge, I was able to spray some DeoxIT contact cleaner on the switch and slide it around a few times.

The switch now works reliably :-)