How to Change Master Company Administrator Email Address?

There is a post titled Change Master Company Administrator Email that has a detailed solution to this problem by a Steve, but it is incorrect. It does allow one to sign in to QuickBooks Business Services from within QuickBooks but it does not allow one to change the email address of the Master Company Administrator. Ours is ten years old and out of date. Support was absolutely no help. In another post, someone described it as a Platform Email Address. Not sure. Regardless, I would hope that SOMEONE at Intuit would have the intuition and intelligence to solve this problem, PLEASE!!!