You need to unscrew the machine screws that hold the handle on from the outside. Then work both the inside and outside handles at the same time, back and forth, pulling on the outside handle slightly. The square holes inside the lock will align (after a little playing around with it), and the handle will come on out. Replace in the same manner. Unless I am sadly mistaken, the gasket under the door handle was originally a paper gasket, something like a water pump gasket, not rubber like you find in the reproduction kits.