The first thing is to pull both the knobs off the controls, headlight switch and dimmer rheostat. They are likely tight, but should pull straight out.

Pop off the plastic cover that was behind the two controls. Insert some sot of thin blade at the edge and pry gently. Very little force reqired.

There are two screws holding in a small metal panel to the left and the instrument cluster to the right. (Later models may have torx screws - not sure.)Remove these two screws and the panel will slide forward. If you are like me place a shop towell to catch the screw you are going to drop.

Remove the wires from both controls. This will allow you to remove the control from the panel at the workbench.

Remove and replace the control from the metal panel.

As the manuals always say: Installation is the reverse of removal.

Note, if more room is required, there are two screws under the plastic panel(s) to the right of the cluster. Pop these off and remove the screws and you can then reposition the cluster to give additional room as required. (Most likely not neccessary.)

Last step -- Sit back and relax with a cold drink of your choice on a hot summer day.

Dan

If you've never had the need to turn the instrument lights down, and I've never had to on any of my 240 Bricks, just disconnect the dimmer and solder the two leads together by passing the rheostat ... insulate with a bit of heat shrink or good quality eletrical tape.
The dimmer controled lights, will over time become dimmer and dimmer over time. This fix will keep the instrument lights at their brightest. To get at the dimmer, pull it's control knob and the light switch knob off ... carefully pry the plastic mounting plate off and you will expose the dimmer rheostat. Hope this helps.