You have to remove the knob shaft first, then unscrew the bezel nut, unplug the wire pigtail and do what you just did backwards to put the new switch in. To get the knob shaft out you have to pull the shaft out to the position that has the headlights 'on' and push the release button on the switch housing and pull the shaft the rest of the way out. If you look at your new switch you'll see the little release button on it so that you'll know what you're looking for.
