The best way to reconfigure the server would be the configuration wizard. There's a file in the openfire/conf folder named openfire.xml
In that file there should be a line named <setup>true</setup>
If you change it to <setup>false</setup>
Then restart the server you can go trough the initial configuration wizard. It won't reset the server configuration, just allow you to change the initial setup, including LDAP, and admin users.
