Use jar xfv redeemer.worker.war WEB-INF/redeemer-servlet.xml to get the current configuration out of the war file
Change the database connection settings at the end of the extracted file
Use jar ufv redeemer.worker.war WEB-INF/redeemer-servlet.xml to update the file in the war archive
Now adapt the driver configuration in driver-config.xml to fit your needs
Copy the redeemer.worker.war file to $JBOSS_HOME/server/default/deploy
Do a tail -f $JBOSS_HOME/server/default/log/server.og and see if any errors occur
If the startup succeeded (could take several minutes the first time!) you should be able to access the admin login screen
You need to manually add the first user via a database frontend (ex. phpPgAdmin) - just fill in the nickname and password (md5!) and set the admin flag to true
