I suspect its not possible to replace just the bearings though if you can get them off the motor an engineering supplies place may have suitable - mine on an HC350 look fairly standard but I have yet to try removing them.
Whole motors are offered by several places
www.espares.co.uk
http://www.shouldersofshoreham.co.uk/
dont know about your model but they are looking for £40 for the one I need
Frankly I think it ridiculous that they have failed after about 10 hours use!
oldgadgetboy
April 2007