So here we go again, some recommend WD40, some don't (me, myself!):
WD40 is a great product, I use it on cars, motorbike, bicycle, but not a DSLR, it is too rough for it. Of course it will work, can last, but then the contacts are over and done with.
A mild tuner-spray (tuner contact-cleaner) is the best, I only have European products at hand which won't be of any use to you in USA or Canada.
So you need to do this research yourself.
You also never ever spray WD40 (or anything better) just into the tiny gap of the e-dial or underneath the mode-dial, to much mess and the danger of severe damage,
there is a lot of electrics underneath and nearby, kind of a sledge-hammer method.
HERE you find a good tutorial how to fix the e-dial of the K-x, which is almost the same!
And HERE: a video how it is done with the K-r.
The K-x tutorial is good and precise and shows you why it is pretty useless to spray stuff into the gaps
but obligatory (and very easy) to just lift the top off.
You don't need to get the bottom off, no front, just those screws:
1 x inside battery chamber (very important)
2 x screws pop-up flash (maybe the third screw there as well, with the K-x definetely not, but it won't hurt)
2 x screws behind the rubber eye-piece
2 x screws where the belt is fixed to
1 x screw right side (the top screw only which is not hidden) right side = side of MF-M switch
1 x screw hidden on right side behind rubber (the top screw)
(maybe one screw on the left side, cannot remember anymore, too long time ago I opened a K-r)
The video is pretty good to show hwo to do the cleaning.