Change Widget's image in C++

I have an Widget that I want to control from C++.

For text content I use bindings to values from my Widget’s base C++ class:

class EP1_API UMyWidgetBase : public UUserWidget {
...
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Menu")
		FString option1Value; //binded later in Widget
...
}

But how to change the Image I have inside this Widget, to another one?
If I declare the image inside C++, I don’t know how to bind it in UI in UE4 Editor.
If I declare it inside UE4 Editor, I don’t have access to it from C++.

And there’s no binding for Image itself. If I click to bind Brush with image, it only generates the getBrush method (which I believe returns copy and not the reference therefore is not useful for me, even if I would be able to go down to Image from it).