Here's a carbon brush replacement video for a similar motor to the DC01 and other Dyson motors. http://www.youtube.com/watch?v=pO6IGz4JmtM
Carbon brushes for Dyson motors are also very cheap on ebay, under £3 with postage, search eBay or goggle with 'CARBON BRUSHES DC01' (or replace for DC02 etc), hope that helps. I'm just someone researching the replacement of mine and am not associated with any leads above.
John
February 2011
Same question problem, having had the DC01 die with a bad burning smell have removed the motor and can see a brush has broken down. Having looked on Google see a number of places selling these so assume they can be replaced for a lot less than a new motor, worth trying for £5 as think our machine is too old to warrant £45 for a new motor.
The next question is how to remove and replace them in the motor itself!