Lay the machine on its back, and undo the 3 plastic screws 1/4 of a turn, and lift the sole plate clear. You can then lift the bristle brush out, but you'll be pulling against the rubber drive belt - its like a thick rubber band. The brush has a spindle running through it, and by pulling away the end bearings you'll be able to replace the brush with a new one.
John
April 2009