Admin Console Security in Geronimo 2.0.2

[tglawles]

How do I change the default properties file base authentication in Geronimo 2.0.2?  I would like to harden my Geronimo install by restricting access to users who belong to a specific group within my ldap directory.  I'm able to successfully create a new ldap realm and authenticate users off it, but I can't figure out how to reconfigure Geronimo to use my ldap realm instead of the default properties file realm.