They say Germany is Amalek.
Assuming this to be true, and assuming the mitzvah applies to individuals, maybe all you need to kill Amalek is a donation to the German suicide organizations, or better yet, the “German Society for Humane Dying“. I don’t think the size of the donation matters much.
Of course, political campaigning for government funds for assisted suicide and the like is not enough; they must be enabling death in the here and now.