pull off the dash surround, then pull the main knob off the headlight switch, then the dash illumination switch should come off. then once all that is off, i'm pretty sure you can just rotate the back of the switch to unclip it, or there maybe some sort of clip you have to turn.
just don't break the little locating tab on the surround.
yeah the part you actually grab to turn the lights on,get a little screw driver under that and "pop" it off and the rest basically with a bit of turning and twisting just comes apart,just remember how it goes back together