if you want to run the setup again you can edit conf/openfire.xml and change . I have no idea how good this is if you already have users in your database, so you may want to use a new database (for example backup and delete embedded-db/* if you are using the internal database).
The setup will test the LDAP connection, you can try it with your account if login works and if vCards of other users are displayed right. There is as far as I know no guide available which explains all possible configuration settings in detail.