Unplug the machine if it is plugged in and remove the key. Lay the machine down with its handle against the ground to provide better access to the rotor blade.
Remove the screws that secure the panel on the right side of the machine using a screwdriver. Remove the panel.
Loosen the rotor pin using a wrench. The pin is located in the center of the area that was covered by the panel.
Grip the rotor carefully and pull the end that was secured with the rotor pin toward you to remove it.
Insert the fitted end of the new rotor into the machine first. Then rotate the rotor toward the end where the rotor pin was located until the rotor snaps into place.
Insert the rotor pin and tighten it with the wrench. Replace the cover and tighten the screws into place.