Using iCloud for iTunes & saving memory on Macbook

I have a Macbook Air, MacOS Sierra, 10.12.6. I went to do the upgrade to MacOS High Sierra, 10.13.2.


I got a message saying that there wasn't enough memory for the upgrade. I have the 121Gb of storage & it shows I have 12.67Gb available with iTunes taking up 35.16Gb.


I have iTunes being stored in iCloud (50Gb plan), I have iTunes Match, & use Time Machine for backup.


How do I physically get the music out of memory but keep it in the iCloud?

(The same process that I can do with iTunes on my iPhone 6s.)



Using iCloud for iTunes & saving memory on Macbook