I repair Dysons for a living and its no big secret really.
All the tool repair shops use a short bare shafted terminal screw driver.. It is bent 90degs and about an inch in from the end.
Unplug the Dyson first mind.. Grab a can of furniture polish and spray into the switch...
Push the tool into the small hole and lever the switch button out... Ta Da
Thats the easy part, the rest will remain with me till I am on my death bed, which with the amount of dyson bin dust I inhale everyday shouldnt be too long.....
Karlpeg
October 2006