Instead of push segue how to replace view controller (or remove from navigation stack)?

Question

I have a small iPhone app, which uses a navigation controller to display 3 views (here fullscreen):

Answer 1

the swift 2 version of ima747 answer:

override func perform() {
    let navigationController: UINavigationController = sourceViewController.navigationController!;

    var controllerStack = navigationController.viewControllers;
    let index = controllerStack.indexOf(sourceViewController);
    controllerStack[index!] = destinationViewController

    navigationController.setViewControllers(controllerStack, animated: true);
}

As he mentioned it has the following advantages:

• Can work anywhere in the view stack, not just the top view (not sure if this is realistically ever needed or even technically possible to trigger, but hey it's in there).
• It doesn't cause a pop OR transition to the previous view controller before displaying the replacement, it just displays the new controller with a natural transition, with the back navigation being to the same back navigation of the source controller.