That was almost right. I FOUND THAT BY HOLDING THE TOP BUTTON ON THE STALK IN, THEN INSERTING THE CARD IN THE SLOT, THE MPH STARTED TO FLASH. When it converted to kmph I dipped the clutch and THEN pressed the start button. This locked the setting to kmph rather than mph.
I was able to reverse the procedure by carrying it out again. Thanks for your help. You never know what these cars can do - tricky!