Comment by bonoboTP

It doesn't have to be all that dramatic. Just ensure that they don't reproduce at replacement level. In fact that's already happening. Crank it up a bit more, make things South Korea++ and it's just not a problem. If nobody shows up in the next generations out of whatever reasons, there's no risk of some kind of uprising you'd have to crush with a robot army. Just wait, push cultural messaging that encourages individualism and implicit antinatalism and it will seem perfectly humane. Legacy humans will simply go away, without any major incident.