- Poison the water supplies. Without proper water, people will either die of dehydration or become poisoned and die regardless.
- Kidnap their pregnant and kill them. When a population can no longer reproduce, their population will decline regardless of what they do.
- Nuke them. Nothing smells as good as nuclear warfare in the morning. Remember, if it doesn't hurt you, it probably doesn't hurt them much either.
- Shoot them with guns. Trust me, gunfire is as good as nuclear warfare if you're good enough.
- Put them on reality television. This method, although criticized by many, has been known to cause serious bloodshed and death. It's rather inhumane, so it's best if you avoid it.
- Make new laws. Prevent many people from becoming pregnant by only allowing a couple to have one baby or none at all.