To sync to a different library, you need to reset or break the sync.
To share a library:
Screenshot of EndNote 20 for Windows File menu option and Sharing window by Clarivate. Click for larger versions.
Screenshot of EndNote 20 for Windows File menu option by Clarivate. Click image for a larger version.
Screenshot of EndNote 20 for Windows Sync option by Clarivate. Click image for a larger version.