To update your address, simply go to your account dashboard, then under "Account Details" click on "View Addresses". Here you may add, delete or edit your address. Make sure the "Default" address is the address you want the box to be shipped to.
To change your shipping address, go to your account dashboard -> "Manage Subscriptions" -> "My Subscriptions" -> "Edit" next to your address under "Subscription Orders".
Please remember, all address changes need to be made prior to the 1st of the following month. If it's not updated by then, your box will go to the default address on file.