when you look at the push button from the top,you will that it has a flat side. find something that will slide down the flat side, e.g. a feeler gauge etc, push this down until it displaces a catch on the inside of the switch.its a bit fiddly but the button will slide up out of the housing.you will find a philips screw holding in the button enclosure.after that its a doddle to repair the mains cable.
stewart (also an electrician)!
stewart dobing, November 2005