Overwrite interface function

I don’t understand how I can overwrite an interface function. I can implement an interface function (from a interface blueprint) with an event. But how do you overwrite the function like in the UE4 documentation. Does the documentation mean that you should implement the interface function with an event in a Parent class and then overwrite the function in the child class?:

I’m going around in cirlces myself with the Blueprint Interfaces. When I try calling them from another class nothing happens, double clicking into it takes me to the non editable function on the Interface itself.