The following is what I used, it only requires editing the comments.php and it kept the custom styling I already done on my comment form.
In comments.php, I replaced the last line with:
$defaults = array(
'fields' => apply_filters( 'comment_form_default_fields', $fields ),
'comment_field' => '<p class="comment-form-comment"><textarea id="comment" name="comment" cols="45" rows="10" aria-required="true"></textarea></p>',
'comment_notes_before' => '',
'comment_notes_after' => ''
);
?>
<?php if ( function_exists( 'comment_form' ) ) comment_form($defaults) ?>
Doing it like this, I don’t have to worry about having to back up the theme function.php if something goes wrong.
