Vocoder Problems (Mainstage 2)

Hi everyone - I'm just getting into MIDI music cretion and purchased Mainstage to help accomplish this in a live setting. I'm having problems getting the Vocoder to work though. I've read through some of the posts in this forum and tried looking at articles online, but I'm afraid I'm too much of a noob to even understand that. I was wondering if anyone could walk me through how to get it working like in this video (http://www.youtube.com/watch?v=kmRSyVrimL0) that would super helpful. Thanks in advance!