Half a Page of Scribbled Linux

From XML.com:
From your web browser, go to https://<tivo IP>. The username is "tivo", and the password is the Media Access Key from the TiVo's System Information screen.

Download the video. It'll be in a .TiVo format, which can be converted to MPEG with Tivo File Decoder. Instructions to build it are here. To run it on a downloaded video from TiVo called sitcom.TiVo:
$ tivodecode -m <media_access_key> -o sitcom.mpg sitcom.TiVo