I have had the most reliable results using Method 3.
The following will work on most ISP provided modem/routers when the Time Capsule is operating in Bridge Mode behind the modem/router. You will need to check with TWC on specifics if they provided the modem/router to you.
Verify that you have a fixed, static WAN Internet IP address from TWC for the modem/router....not the usual type of IP address that will change on a regular basis. Expect to pay an additional fee for the fixed WAN IP Address. Some providers will only provide a fixed IP address with a business account. Check with TWC for details.
Configure the TWC modem/router to provide a fixed, reserved local IP address for the Time Capsule on your network provided by the TWC modem/router. An example might be something like 192.168.1.50.
Assuming that the TWC modem/router supports Port Forwarding.....set up the modem/router to forward the following ports to the fixed IP address on the local network that you have established for the Time Capsule.
Public UDP Port 8888
Public TCP Port 8888
Private UDP Port 548
Private TCP Port 548
To connect from a remote location on a Mac laptop:
Click anywhere on the open desktop so that the Finder menus are displayed at the top of the screen
Click the Go menu
Click Connect to Server
Enter the following......"afp://" followed by the static Internet WAN IP address of your modem/router followed by a colon ":", then enter "8888"
Example, assuming that your fixed WAN IP address for the modem/router is 12.34.56.789......enter the following in the Connect to Server box:
afp://12.34.56.789:8888
Then, enter the device password for the Time Capsule to connect.