Access your base station using Back to My Mac
You can use Back to My Mac to access your base station to monitor the network or make changes to the base station’s settings. You can also access the hard disk built into the AirPort Time Capsule, or an external USB hard disk connected to the AirPort Extreme or AirPort Time Capsule.
Before you begin the setup process, be sure that you’re set up to use Back to My Mac. For information, see Use Back to My Mac and the Apple Support article Set up and use Back to My Mac.
Open AirPort Utility, located in the Utilities folder in the Applications folder.
In the graphical overview, select the base station you want to configure, then click Edit. You may need to enter a password for the base station.
Click Base Station, then click the Add button
below the Back to My Mac list. Enter your Apple ID and password, then click Sign In.
You can optionally add additional Apple IDs and passwords.
When you’re done, click Update to save your changes.