Simple filter to change label name of Email Adress to something else

add_action( 'user_new_form', 'change_label_form' );
function change_label_form() {
  echo '<script>
  jQuery(document).ready(function($) {
    $("label[for=email]").html("Example");
  } );
  </script>';
}

here is trick worked for me , you can change the label for any filed by using the for tag in the label and you can add action on any form you like, as

add_action( 'edit_user_profile_update', 'change_label_form' );

Here is another trick you can use

add_action('admin_head-user-edit.php', 'setup_user_edit');

function setup_user_edit() {

  add_filter('gettext', 'change_profile_labels');
}

function change_profile_labels($input) {

if ('Email' == $input)
    return 'Example';

  return $input;
}