Delete photos from iMac but keep in iCloud
I recently reconfigured an old iMac of mine to 500GB of SSD storage as a second computer. While installing an OS update I accidentally allowed iCloud to fill Photos with everything from the cloud taking up half of my SSD space! How do I delete the collection on the iMac while keeping the photos in iCloud? I'm afraid of accidentally losing all of my photos. Should I just delete Photos from the computer and the collection along with it?
iMac Line (2012 and Later)