How do I add a third party plugin in main stage

Hi,

I have the latest version of mainstage and I just downloaded Lounge Lizards Rhodes sounds. It has a stand alone application, but I want to use those sounds in mainstage...

How the heck can I do this? I've looked everywhere, and it's not recognised in the AU or instrument section at all...

Maybe I'm going about this the wrong way?

I'm brand new at this and I'm reading through the manuals. Still don't think it covers it that well?

Just so you know, I added NLogPolySynth successfully, but mainstage recognised it whenever I started up mainstage, so it was all automatic.

Thanks!