Hi there,
Isolate the mains supply first, then take the top off by undoing 3 screws & slide it off.
The motor is on the top & the brushes are held in with small plastic tangs, press these in & lift the brushes out, the bottom one is a bit fidderly, Take the spade connectors off & reconnect the new brushes, On the plastic part of the brush there is a metal retainer which has to be moved to allow the brush to spring out, once this is done push the brush into the holders & it should be job done.
Put the lid back on & test it, it may make a slightly louder noise but this is normal as the brush has to wear in to the communicator.
Rob, July 2007