Get and install python first.

unpack napyrc into a directory.
Edit config.py
If you decided to use cached list of shared files, prepare
  the file "shared"
run napyrc.py
run your IRC client, as nick use your napster nick, as server give
the computer you run napyrc.py on (usually localhost)

So far napyrc is fragile, but already usable. Having said 
that, use it only if you know what are you doing :-)
