Veamos... vas a editar tu el archivo index.template.php hubicado en la carpeta:
Themes/classic/index.template.php
y vas a buscar esta partecita:
</form>
</td></tr>
</table>';
// Show the "Powered by" and "Valid" logos, as well as the copyright. Remember, the copyright must be somewhere!
echo '
<br><a href="http://www.oaxaka.net/" target=_blank title="Oaxaca en linea">Oaxaca</a><br>
<br />
<table cellspacing="0" cellpadding="3" border="0" align="center" width="100%" class="tborder">
Modificas esto:
<br><a href="http://www.oaxaka.net/" target=_blank title="Oaxaca en linea">Oaxaca</a><br>
por esto:
<a target="_blank" href="http://www.oaxaka.net/foro/"><img
src="http://www.oaxaka.net/oaxaquenos/img/106.GIF"
alt="Visita Oaxaca"></a>
Autor