Turn off Icloud without losing desktop documents

If you choose to turn off iCloud Drive entirely, ie: not just Desktop and Documents, iCloud will download your files as described below in highlight. Once done, you can deselect desktop & Documents and turn iCloud Drive back on again.

Same result, less effort.

See >>> https://support.apple.com/en-ca/HT206985

I would temporarily create two new folders on your user home folder - outside the Documents folder.

• A folder named DesktopLocal
• A folder named DocumentsLocal

Then drag all files and folders from your Desktop to DesktopLocal and drag all files and folders from dour Documents folder to Documents Local.

Once all files and folders have been moved to your local folders, disable Desktop&Documents for iCloud Drive.

Then move the items from your temporary folders back to the original Desktop and Documents folders, that now should be again back to normal.