Update: As of BuddyPress 1.1 this can be done via the wordpress aministration area. You can find this in BuddyPress > General Settings on the left side menu.
Those that use BuddyPress along with their WordPress MU installation may have found some limitations with the xprofiles. BuddyPress Devs have improvements listed as an upcoming feature, but in the meantime some things need to be fixed NOW!
One particular feature I needed to get round was the fact that you can’t change the default “Name” field. Whilst very common to have this as a field in most installations, we should at least be able to edit the field names the user sees, but unfortunately this is not so.
There is a way of changing this, but requires you go into your database, via phpmyadmin or something similar.
There’s two places where you need to make changes. Here are the two SQL statements you should run (note you may have to change your table prefixes here if you installed wordpress with different ones):
UPDATE `wp_bp_xprofile_fields` SET `name` = 'newnamehere' WHERE `wp_bp_xprofile_fields`.`id` =1 LIMIT 1 ;
UPDATE `wp_sitemeta` SET `meta_value` = 'Nickname' WHERE `wp_sitemeta`.`meta_key` ='bp-xprofile-fullname-field-name' LIMIT 1 ;
And now go back to your buddypress fields and voila!