If he absolutely wants it removed, couldn't he just log in himself and do the work? Why rage over the fact that someone doesn't want to clean up your mess? ,.. or case in point, a castle.
It's your server anyways, so you can do what you want with it... delete the whole world, or upload the world files for the whole world to download and we'll party in his castle, wearing tight things around our necks and eating cheesecake.
Regardless, you can do what you want, so just do what you want.