To remove a cloud access of any user, you log in as admin in the Configure Cloud Access.
For that, in the Configure Cloud Access select admin user.
Click the Sign In button, and fill in the dialog box.
If the user you want to remove the cloud access off has at least a read access to one share, you can remove it with the basket button !
This is almost explain here : Turn Off User Cloud Access
Once, the user shows only Invite button in the Configure Cloud Access panel, you can remove it from the Set Up Local Network Users panel !