Thread: editing state Field

editing state Field

Hi, I would like to modify the state field to include canadian provinces values, but I cant modify the firld because it's greyed out.

I know this issue has been addressed and the solution is: Replace line 430 of the file /includes/admin/admin-options.php ...

But I Can not find: /includes/admin/admin-options.php

I am using version 3.0.2.. my root structure is somthing like:
-wp-admin
-wp-content
-wp-includes

Thank you for your help