FreeBSD specific virtualmin installation / configuration

Would someone kindly point me to FreeBSD specific installation / configuration information. It doesn't appear possible to install virtualmin within webmin as that returns weird / cryptic 'something broke' messages. Installing the relevant port appears to work but virtualmin doesn't appear in the list of webmin modules. Needless to say it also doesn't work. Linux documentation isn't relevant, in particular it goes on about an install script that doesn't exist in FreeBSD.