Link FCP to a Sound Library on an External USB Drive

I have FCP running on two of my machines, a Mac Pro and my MBP. I just successfully relocated my entire Sound Library and a couple of project files (in a folder called Logic) to an external SSD USB drive. That removes about 68GB of data from my HD.

Now I want to relocate or simply link to this Sound Library on the external drive, on my MBP. Make sense?

If I select Relocate Sound Library, my external drive (containing the entire Sound Library) is shown, but it's greyed out and the status indicates "Sound Library files exist here."

Well, how do I tell FCP to use this library?

"Open Sound Library Manager" doesn't offer any option to do this.

I can change the Audio Recording Path in Project Settings, no problem.

What am I missing?