Loading 3rd Party Maps on my Garmin Zumo 660

I'm so frustrated. I bought a CD from Sound Rider a couple years ago in hopes of loading the routes on my Garmin Zumo 660. The maps are supposed to be compatable with Garmin GPS's, but so far I have not been able to get them to load, or at least not to a place where I can find them.

Can anyone guide me through the process of properly loading and finding these routes? I'm beyond frustrated!

Thanks!