Changing a UiView without a viewcontroller via swipe

I am attempting to update a inherited xCode project. Essentially I am drawing a blank at attaching a action to the swipe gesture that I have integrated into he project. I have only ever previously done this with storyboard but due to the age of the project this is not an option.

Currently I have a view controller which houses a pop-up of a separate UIView. The user is to then swipe back and forth through three pages of content. There is also another pop up but this is only one page and therefore does not require the functionality. I can see that the device is recognising my swipe (through output) but I don't no how to attach an action to navigate to the other UI views held within the controller.......Or if this is even possible and I will have to rethink how I have implemented this. Any assistance is appreciated.

Thanks