Here's a quick guide on how to use them.
First of all, you will need to open an account at www.google.com/webmasters/tools and register and verify your account.
Next, you go to VidZapper and select Distribution > Export.
Select your Channel and Playlist, then the MRSS format and add your Player Base URL and DirectLink URL so that the resulting video in played in your website and not the video player directly.
Then click 'Generate'. You can then cut and past the resulting file on the right hand side into a notepad file. This is your MRSS sitemap for this playlist. You can repeat the exercise for any other playlist you wish to submit.