Really pretty simple. That's if you've got the Time Capsule and your Computer set up correctly.
Time Capsule setup:
1. Open Airport Utility
1a. Open Time Capsule Base Station tab
1b. Put iCloud NAME in "Back to My Mac"
1c. Enter Password, then wait for activation (less than 1 minute normally)
1d. Open Time Capsule Disks tab
1e. Check mark "Enable file sharing"
1f. Check mark "Share disk over WAN"
1h. Password self explanitory
1. Open iCloud in System Preferences
2. Put a check mark on "Back to My Mac", wait for actication (less than 1 minute normally)
Connecting to Time Capsule Disk from you HOME network or outside your home network ((INTERNET))
In order to connect to Time Capsule Disk off your local (home) network you must have an internet connection, if you do then do this:
1. Open Finder
2. In Finder open Shared if collapsed and double click on your Time Capsule name.
3. Double click your Time Capsule, enter password (if you required).
4. Once connected to your Time Capsule double click on your Disk to mount it enter password (if your required).
5. Done, remember the connection speed is dependent on your internet quality (broadband vs dial-up).