How can I get TV shows off my iPad

- I bought some TV shows on my ipad. They are only on my iPad.
- iTunes is set to sync manually for this iPad.
- I've never synced TV shows (iTunes is set to "don't sync") for this iPad with any computer
- When I turn on syncing for TV shows in iTunes, it wants to erase the content on the iPad

How can I copy the shows from my iPad to my computer?

Thanks!

Jon