Follow the procedure below.
Hard Drive Replacement in Case of Disk Failure Other Than Drive 1 or Drive 2
1 Double-click the icon on the desktop to start NAS Navigator2.
For Mac OS, click the icon in the Dock.
2 Right-click on your TeraStation’s icon, then click Open Remote Desktop. For Mac OS, click the TeraStation’s icon while holding down the control key, then click Open Remote Desktop.