Here are the following folders and their corresponding paths:
(Note the difference between the Logic in ROOT Application Support vs. the Logic folder in USER Application Support. )
Apple Loops /Library/Audio/
Apple Loops Index /Library/Audio/
Audio Music Apps /Library/Audio/
Garageband /Library/Application\ Support/
Logic /Library/Application\ Support/
Logic ~/Library/Application\ Support/
Here's the symlink syntax: sudo ln -s [source] [target]
Disclaimer: I am not responsible for any loss of data, damage to software or hardware components, or other issues that may arise from following the instructions provided in this video.