Here are the simple steps to clean a 1951 Nikon S Rangefinder camera. I’ve read that the Nikon One and Nikon M are similar except for the Accessory shoe does not need to be removed on the S. Also the film advance knob does not need to be removed, but for cleaning, simple loosen the set screw and unscrew the knob (ccw)
remove rewind knob-1 | remove rewind knob-2 | remove shutter button guard |