Right click the changed .ear file and select Deployment -> Redeploy.
do you have WTP installed or how can you see a .ear - file in eclipse? Which view/perspective do you work with to see an .ear - file. I followed the howto on page "http://wiki.jboss.org/wiki/Wiki.jsp?page=UseJBossEclipseIDEToDoJBossSeamsBookingExample". As a result I have a src-folder in eclipse - package explorer with the java - files of the exmple but not an ear. I work with eclipse3.1 an JBoss-Ide1.5.