I'm locking this topic now. While there are many ways to skin (and apparently kill) a cat, we're verging on incitement to commit a crime.
Leghorn, I'd advise strongly against doing any harm to the cat. If it were feral it seems you could legally shoot it. However, since you know it has an 'owner' (however badly they care for it, or how little time it spends in their house), it's likely to be domesticated in the eyes of the law and you'd be committing a criminal offence.
egbert and others have provided good advice that doesn't involve harming the cat, and they seem like the avenues to explore.
Thanks,
Dan