I carried out this repair ages ago. Although you could still select reverse (and all the other gears), my reversing lights didn’t work, and my passenger side rear view mirror didn’t dip.
The replacement is very easy, but a new switch will cost you £30 - £40.
Select first gear and remove the allen bolt from the back of the gear selector handle.
Hold the lever in on the handle and remove the handle by pulling it upwards.
Using a hooked tool, lift up the two far corners of the console wood trim.
- Select second gear and lift the far edge of the trim, then move it away from you to release the near edge
Carefully lift the trim and turn it over, then unplug the gearbox mode switch.
Remove the two allen bolts from the old switch, select neutral, and lift the switch out. Unplug it and replace it with the new switch.
To make it easier to put the trim back, push out the mode switch from behind before you replace the wood. Then fish the plug from out of the hole, plug it back in and push the mode switch back in place.
- Replace the selector handle and screw it back on.
The old, broken switch (disassembled)