You must have python installed (at least version 2.3, or version 2.2. with optparse package)

edit first line of pydf to point to your python interpreter,
copy pydf somewhere into your path, 
copy pydf.1 where your manpages reside (e.g. /usr/local/man/man1)
and copy pydfrc into /etc/pydfrc, or ~/.pydfrc

Modify /etc/pydfrc according to your taste.