This example shows how to change the default set of buttons in the toolbar.
// default set of buttons
'html', 'format', 'bold', 'italic', 'deleted', 'lists', 'image', 'file', 'link'
// additional set
'line', 'redo', 'undo', 'underline', 'ol', 'ul', 'indent', 'outdent', 'sup', 'sub'
So you can customize the set with the buttons
option like in this demo:
<!--element -->
<textarea id="content"></textarea>
<!-- call -->
<script>
$R('#content', {
buttons: ['redo', 'undo', 'format', 'bold', 'italic', 'ul', 'ol', 'link']
});
</script>