Changing the registration form
The easiest way is to create a custom module and use hook_form_alter():

function mymodule_form_alter(&amp;$form, &amp;$form_state, $form_id) {
  if ($form_id === 'user_register_form') {
    $form['account']['name']['#title'] = t('Full name');
    // perform other changes here
    // var_dump() or krumo() the contents of $form to see what you can change
  }
}


If you prefer you can also a variation of hook_form_alter to target the form specifically instead of having to do an if

function mymodule_form_user_register_form_alter(&amp;$form, &amp;$form_state, $form_id) {
  $form['account']['name']['#title'] = t('Full name');
  // perform other changes here
}