Down the side of the on/off switch when viewed from the top is a tiny hole. In theory you put a small screwdriver or thin blade down the side of the switch, depress a spring tag built into the switch button and the button then comes out. Below this a screw, undo to remove and rewire switch. I only found out the hard way (by breaking it first). Hallelujah for Araldite.
schomosport, July 2004