I've just repaired my DC04 using the link http://www.sparesaver.com/technical_advice/Hints_Tips/DC04_Hints_and_Tips/DC04_Cutting_Out.htm
The right angled screwdriver part requires some patience. In the end I had to use a couple of small, bent screwdrivers to ensure the catch on the glamour cap was fully pushed in before you can work the cap out. Use a blunt knife first to separate the housing from the switch cap - just so you can have a look to see exactly which part of the glamour cap is the catch.
Dave
December 2006