Hi,
you can do this by adding in user row the extra fields with own API (see docs at http://docs.easy-profile.com/index.php/article/jsnuser-object), the file to edit is /administrator/components/com_users/views/users/tmpl/default.php. Alternatively, instead to edit a Joomla core file, you can create an override for this file by coping it to /administrator/templates/isis/html/com_users/users/default.php.