I am not computer literate. Several years ago I installed Roon on my 2013 MacBook Pro to manage my iTunes library. I don’t recall any major difficulties installing Roon. Recently I decided to replace Roon 1.8 with 2.0. I foolishly deleted Roon 1.8 only to discover that the OS of my Mac cannot be upgraded to an OS compatible with Roon 2.0. I need to reinstall Roon 1.8. I cannot get past the point where I am supposed to set up some sort of folder. How do I proceed?
You should not need to do this on your Mac - just download the installer and run it.
Follow the steps in the Migration FAQ to move back to 1.8 (Legacy).