Installation is really simple:
- make sure you've used iTunes at least once (under Windows or Mac OS X)
- have at least one song on iPod
- copy the libfmodex audio library to /usr/lib (root priviledges needed). You'll find this file in the package you've downloaded
- mount your iPod somewhere inside /mnt or /media with read/write access
- make sure you have the df command installed, which is usually part of any standard linux distriburion.