Multiple servers

Hello, I recently spotted that freeradius 2.0 can do multiple instances in one go. I have two raddb directories that works for each server at the moment is there easy way to make them instances on the same server? I looked at the example configuration files but I did not find any server clauses or listen in sites-enabled directory.Should I just put listen clause in one of the files remove the default file there and remove listen from radiusd.conf ? Regards Paul