How to get rid of zombie army?

[Quaggle]

I accidentially created a zombie army bcoz i have followed the professor's recommendation to investigate scientifically why zombies emerged in one of my towns. it seems that i didnt read the part with military applications. i still don't know anything about theses zombies but at least i hired these creatures for my army

so does anyone know how to get rid of the zombie army i feel a little bit inconvient having these brain-eating things around how i can dispose these zombies?