Restore it using iTunes selecting as a ne wiPod when prompted.
Hi Sparkee. So what is the difference between "Restore" in iTunes, and "Erase All Content and Settings" in the General-->Reset option on the iPod itself?
Also, since I am manually managing my music, I erased the music library by shift clicking the songs on my iPod
in iTunes, and deleting the songs from in iTunes. (Not the iTunes library)
I ejected the iPod, turned it off and on, ( it wouldn't show that my music was gone on the iPod itself without doing this), then recopied my library. The only thing was I had to delete and recopy the playlists I'd made, as they were now empty.
I found later that the music on the iPod can be deleted in Settings-->General-->Usage-->Music-->edit and delete it, although it would be a good idea to clear the iPod music list in iTunes (for the iPod) to prepare it for a sync.
It occurs to me though that creating and syncing selected playlists is probably the way to go.