Download the agent from [[http://www.sun.com/download/index.jsp?cat=Identity%20Management&tab=3&subcat=Policy%20Agents|here]]
extract the archive, and run the script //j2ee_agents/am_tomcat_agent/bin/agentadmin// with --install argument.

Note: you must know the server key before run this scripts.

Once the install is finished, rename (or link) commons-modeler-2.0.jar to commons-modeler.jar in the //server/lib// directory.