You can't.
However, if you are in possession of an Xport/Sharkport I can supply you with a, blank sadly, saved game for your region using the other measurements - I guess you are Canadian wanting to switch mph to km/h?
If you don't have an Xport/Sharkport, I don't think there's any possible way to do it. And you SHOULD have an Xport/Sharkport - it connects a memory card in Slot 1 to your PC through a USB, so allowing you to backup saved games to the Hard Drive and never needing another Memory Card.
Xport for PAL/Europe (and Australia. And S. Africa) users.
Sharkport for NTSC (USA/Japan) users.