Undeletable videos on iPod Classic

I have several videos that are taking up a lot of room on my iPod Classic, and I would like to delete them.

The problem is that these videos do not show up in any of the listings from which I can delete them; this "listings" I'm referring too are Music, Movies, Podcasts, and Books. (They do show up in playlists, but this does not help my cause; selecting these videos through such at list at most lets me delete them from the playlist.)

FWIW, the media kind for all these videos is iTunes U. I am not able to change this media kind in the Get Info > Options dialog, because the option is grayed out. (For no other item in this iPod do I see a grayed out Media Kind option in this dialog.)

My question boils down to:

How can delete these "zombie" videos?

Possible complications:

1. The version of iTunes I'm using is 9.2.1. (Version 10 was hatred-at-first-sight for me, and I have never given it a second chance.)
2. The iPod is hugely out-of-sync relative to my main iTunes library. I have disabled automatic sync-ing, because my main iTunes library is far bigger than I could fit in this iPod, even though, over the years, I have deleted stuff from my main iTunes library that I still have in my iPod. (In general, I find iTunes' sync-ing behavior too bewildering, therefore disabling automatic sync-ing is the only alternative I consider safe.)
3. If I select the iPod icon in iTunes, and choose the iTunes U tab, all the controls on the resulting screen are grayed out. (This is possibly related to [1] or [2] above)¹.

Thanks!

¹ Complication #3 above suggests that I may be able to get some traction if I were to enable synchronization, since this could (conceivably) result in a re-enabling of the currently disabled iTunes U tab. Unfortunately, doing so would, of course, set off synchronization, which I most definitely do not want. One possibility would be to create a new empty iTunes library, start iTunes with this empty library as its library, and then enable synchronization. This would ensure that nothing gets copied from my laptop to the iPod (or so I would hope), but it does not guarantee that the contents of the iPod would be left untouched. (How do I know that the sync-ing wont cause the entire contents of my iPod to be wiped out?) Of course, in any case, even if I can turn-on auto sync-ing safely, it's anyone's guess whether this will lead to an ultimate solution to the problem of deleting the unwanted files.