Be aware that if you do this you are using the Sun JSF Reference Implementation. JBoss 4.0.3 will ship with MyFaces which will probably mean that you will need to either disable MyFaces or rip out the JSF jars from your WAR.
See http://wiki.jboss.org/wiki/Wiki.jsp?page=JBossFaces for more on this.
If you want to convert this to a MyFaces portlet you will also need to change your portlet.xml file.
See http://myfaces.apache.org/docs/portlet.html for details on that.
Also, this wiki is based on Java Studio Creator 1.0, but some of the info may still be relevant: http://wiki.jboss.org/wiki/Wiki.jsp?page=JavaStudioCreator