How can I format Time Capsule?
- Launch the AirPort Utility.
- Select the Time Capsule whose disk you want to erase.
- Hit the "Manual Setup" button.
- Click the "Disks" icon button.
- Click the "Disks" tab.
- Select the disk (not a subvolume, the disk itself).
- Click "Erase...".
- Follow the dialogs from there.