Unplug your machine from the mains and remove the top. Look around the top right/left of the machine for the motor. On either side of the motor there should be a wire, disconnect these wire making a note of which went to which side. Where the wires connected to the motor should be a small unit (about 1 to 2 inches long) held in with a clip. Remove these 2 units. Each unit should have what looks like a spring loaded piece of stone coming out of the end that is about 1/2 to 1 inch long. These are your brushes. take them to a spares shop and they will be able to replace them for you. Insert the new brushes, reconnect the wires and replace the top.
Steven Graham, August 2006