Mark, Not sure if this helps, but I have a DC03 (approx 6 yrs old), so not sure if the same power switch as the absolute plus.
Anyway, I had a similar sort of problem - to remove the yellow plastic cover need to gently prise the edges of the main upright housing unit away from the switch cover and the plastic cover can be easied out (basically it's has 2 ball tabs which slot into sockets in the main housing to allow the rocking motion for on/off along with a spring). Once this cover is off there's a single screw which holds the electrical part of the on/off switch in, take this out and the unit comes away easily. Biggest pain after this is: the cable was glued into the flexible plastic protector just as it enters the unit - took ages to get bits out ...)
Sorry if not clear but it's hard to describe
Pete
July 2004