Removing/changing certifiers/OU

Hi, we have notes running for about 700 users with all users something like:

John Smith/1*/MACDOW/AU

where 1* is different based on there location; eg, Australia, Singapore etc.

How can I get rid of the /AU at the end as obviously it is not required and it was originally setup - before my time! :wink:

Cheers,

Jason