Per the instruction manual, with the motor off you can turn the belt to the off position, attach the felt floor duster to the bottom plate and clean your wood floors.  I have used my Kirbys this way but find it more convenient for navigating around/under dining tables or beds to use to the hose setup with the "surface nozzle", with or without the felt pad.

If you use the Kirby in upright mode for cleaning bare floors just be sure to release the belt when you're done or it will get stretched out of shape!