Add this to functions.php to unset and add fields in the user profile section in the backend.

social-fields.php

function extra_contact_info($contactmethods) {

unset($contactmethods['aim']);

unset($contactmethods['yim']);

unset($contactmethods['jabber']);

$contactmethods['facebook'] = 'Facebook';

$contactmethods['twitter'] = 'Twitter';

$contactmethods['linkedin'] = 'LinkedIn';

$contactmethods['googleplus'] = 'Google+';

 

return $contactmethods;

}

add_filter('user_contactmethods', 'extra_contact_info');