[otrs] Changing the name of a field

Hi all, I'm trying to rename a field on the customer. To start with it's just the Customer Id, is there any way of renaming this field without creating a new template? It's just a cosmetic change, just on the html that our call centre sees. I've tried various things but always seem to break the whole app. I used to do a lot of Perl but am very rusty now. Thanks for any advise you can give me. Tim