Nilfisk HDS2000 and Nilfisk GD2000 commercial vacuum cleaner motor fan unit cassette. Held in by just 4 screws, these are designed to be replaced by the operator in minutes. Unplug before beginning the replacement.
Also check the condition of the HEPA filter after removing from the old unit and re-installing on the new motor. If the motor is burnt out, the HEPA cartridge, could be choked with carbon and should be replaced at the same time.
Check it's condition by raising the filter to the sky, dirty side towards you. Looking up, you should be able to see light through the pleats. If you can't it needs replacing.
SAFETY WARNING! All electrical parts should ONLY be fitted by an electrically COMPETENT person.
At the moment, as standard postage within Australia, is capped at a maximum of $20, maximise the saving on postage and buy some of the related parts below, such as a packet of dustbags and the foam main filter or a new floor tool!