This one is as easy as it gets. You simply create a class which exposes a simple API and hides the complexity behind it.

Facade pattern code example:

public class Facade {
    public int simpleCall() {
        ComplicatedObject1 obj1 = process();
        ComplicatedObject2 obj2 = processAgain(obj1);
        return obj2.getTheMeaningOfLife();
    }
}

https://www.atlasobscura.com/places/sham-castle