Very simple - if you follow the hose down to where it fits onto the body of the machine, you will see what is best described as a tab sticking up at the back of that part of the hose. The tab stops the hose from pulling out when you use the machine. Pull the tab towards you and the whole hose should lift out of the body. When fitting the new hose, make sure the tab is clicked forward. Ring the Dyson helpline for a hose and further instructions. The number should be on your machine.
Adge, June 2007