1. Connect an external disk to the Time Capsule's USB port if one is not connected. The disk can be any self-powered, USB 2.0-compliant external hard disk. It will appear in AirPort Utility as an AirPort Disk.
2. Open AirPort Utility 5.3.1 (or later), located in the Utilities folder, in the Applications folder.
3. Click Disks.

4. Select your Time Capsule's Internal disk on the left side of the window. The right side of the window will change to show the "Archive..." and "Erase..." buttons
5. Click the "Archive..." button.
6. You will be prompted to select the AirPort disk that you wish to archive to. If you have multiple external disks connected to the Time Capsule, select the appropriate disk and click Archive.
7. Another dialog appears indicating that the amber status light on the Time Capsule will blink during the archive process. After you click the Archive button, any users still connected to the Time Capsule disk will be disconnected.

The process will begin (you can quit AirPort Utility if you want to).
You may begin using the Time Capsule drive after the status light returns to green.
Important:
- Do not begin an Archive until all users connected to the Time Capsule disk have been disconnected correctly.
- Make sure there is enough free space on the AirPort (external) disk before archiving to the disk.
- Performing an Archive does not delete any files on either disk.