I already have the plasma main dials, and I decided to fit the matching heater dials. The kit comes with a little piggypack connection so that it just connects into the wiring for the main dials, which is a bonus.
You need to remove the centre console.
Pull off the gear lever gaiter and surround.
Remove the central air vents.
So you can push the console's plastic prongs out of the holding clips
Pull off the black plastic outer shroud and then remove the three heater knobs.
Now you can undo the two long screws that hold the front and lightbox to the heater control unit.