removing dead owner from account

Hi,

My page has an owner account that is inactive for more than a year and a half. No articles on the page are tied to this account; 622 are tied to mine. For all purposes the site is mine. However, this other account remains as the owner. I am concerned that this is a security risk for the site and would like it removed as owner from the page. Is there anything I can do about this?

Thank you.