You don't even need TiVo's software.  You can use your web browser, just type in 
https://{tivo ip}/nowplaying/index.html , username 'tivo', password is whatever the MAK is for your TiVo (check TiVo settings, it's listed in there somewhere).  Select a show and download it.  Then use 
DirectShow Dump to remove the TiVo encoding, and you can do anything you want with them from there.