It doesn't get any better than the factory sheet.
Remove the external VR from the plug.
Cut the DF wire off flush with the wiring harness and tape it over. You don't need it.
That's it. The blue wire and brown wires go to the plug and right back out again. You arent' changing anything in the circuit except the DF wire.
No matter what you do, that blue wire has to turn on the lamp when shorted to ground.