How to Terminate Syncing Data with NC and Delete Data Within NC?

I am using NC via web interface and with the NC app 3.13.0 on macOS. I keep synchronized most of the directories in my home directory of macOS with my NC installation. Now I want to terminate some of the synchronizations. I only want to keep the data an my local macOS installation but to delete it in my NC installation.

What is the right procedure in order to keep my local data safely and to delete the data in NC?

I would simply copy the data from the nextcloud sync-tree to another place.

If your place is limited, then you could move the data while the client is not connected and then those files will be removed from the server on next client connection/synch.

Much and good luck,