I haven't taken a real good look. I'm not even sure if this will work. If you have the mod working currently in the theme you're using. Try adding this code to a phpbox.
global $context, $settings, $options, $scripturl, $txt;
echo '<table>
<tr>
<td class="catbg" colspan="2">', $txt['uot_users_online_today_title'], '</td>
</tr><tr>
<td class="windowbg" width="20" valign="middle" align="center">
<img src="', $settings['images_url'], '/icons/online.gif" alt="', $txt[158], ' ', $txt['uot_users_online_today_title'], '" border="0" />
</td>
<td class="windowbg2" width="100%">';
echo '
<div class="smalltext">';
echo $context['num_users_online_today'], ' ', $context['num_users_online_today'] == 1 ? $txt['uot_user_online_today'] : $txt['uot_users_online_today'];
if (!empty($context['users_online_today']))
echo ':<br />', implode(', ', $context['list_users_online_today']);
echo '
<br />', $context['show_stats'] && !$settings['show_sp1_info'] ? '
<a href="' . $scripturl . '?action=stats">' . $txt['smf223'] . '</a>' : '', '
</div>
</td>
</tr></table>';