We don't recommed running separate web/ejb containers.
Co-location performs so much better and you
don't have all the config problems.

If you want to cluster, cluster web/ejb instances.

The good thing about jboss is that you don't pay
everytime you put the ejb container on a different
machine. Which is a primary reason why you will
see a lot of talk about separating web and ejb.

To answer your question directly, get the
jboss/tomcat distro and remove tomcat* from
server/default/deploy
You will need to remove any wars and jboss.net if
it is in there.

Regards,
Adrian