How To Deactivate Dropbox Account | Delete A Dropbox Account
Mac. Click the Dropbox icon from the menu bar and select “Preferences…” from the context menu. Click the “Account” tab followed by the “Unlink This Computer…” button. Click the “Unlink” button when prompted to confirm the action.
You may have to click the small arrow in the system tray to reveal all its icons first. Click the “Unlink this computer…” button located in the “General” tab. Click “OK” when prompted to confirm the action.