How to edit the user profile fields

Hi

I need to change some fields on the user profile, but I am not sure whether this is possible. I have found some plugins that extend the user profile, but I only need to edit the name of some fields or better cancel/hide them altogether (like ‘About Yourself’). I think it should be really easy to at least change the field names, but couldn’t find the HTML form/fieldset on the wp-admin/profile.php either.

Any ideas on this?
Thanks a lot