1. Expose your media content through http on the wdtv (e.g. add a link under /tmp/www-plugins to your media xmount) and test a wget on that url (you will also need to disable HTTP authentication in apache (there is a patch that does just that commited last week to svn)).
2. Hack together a basic script with sed cat and nc to modify the XMLs you captured and replace the media items with the items you pass as parameters.
3. Profit
