Not sure what model you have but on the 1150GS (03) you simply twist the unit and it moves from UK to European setting. The only bugger is that you have to take the screen off to do it but it can be done in the time it takes the train to get through the tunnel. If it is a 1150 have a look in your manual and if you do not have one, drop me a line and I will scan it for you.