If it is a Grey and lime DC04 then buy a pack of Dyson genuine DC01/04 belts which include instructions.
If it is another colour and has a brush control knob on the cleaner head then a whole clutch mechanism has to be fitted. Engineer job really for most people, specialised tool needed to get brush through new belt. Dyson charge all in fee of £55 for full service inc all parts, labour.
Dyson engineer., September 2005
