xyz special fitting tool how does it work

just thought does anybody know how the special fitting tool works for setting up the xyz switch on a td5 auto disco,

or how would you go about setting the xyz switch without the special tool..

I had a look at the diagrams in Rave. It looks like the tool fits over the gearbox shaft on the flats, and then the other end hooks into a recess in the switch. I've never done it, but looking at the picture, I would have thought that you could get the adjustment pretty close by sight, if you mark the shaft before taking the old one off and making sure you can see the angles. In fact it looks like the flats of the shaft should be at 90 degrees to a line from the shaft to the hole at the top of the switch.

Attached diagram showing tool in place.

When I did mine, I used the live data output on Hawkeye to see that the switch was matched to the selector position.

MW