Thanks for the reply Norm, I was able to remove the black connector after turning the white part 1/4 turn clockwise (one would never guess!). It seems to me due to the very tight space, you'd need to drop the transmission to remove that switch? In any event, the wiring looks pretty good still (the car only has 50k miles on it), so I just sprayed some contact cleaner on both sides and put it back together. Turning the white ring back took a bit of leverage with a screwdriver, but everything is back in place now.