Tell them they need to attach it to DIS (the coding and diagnostic computer) and run through the process that they would do if they installed a new/replacement Navicomp in a customers vehicle.

Having said that, my dealer wanted to charge 1hr labour for doing it on my E46 so I basically lived with it not being coded correctly - but then I didn't have the issue of arrival times.

I wonder if its something to do with the wheel sizes on the X series being so different to that of a 7er (which is what it defailts to when you downgrade)?