Cracle删除IDCS用户

Cracle创建了一个新IDCS用户后，尝试删除注册时系统创建的IDCS用户提示如下错误：
是否确实要删除用户 ‘[email protected]’？"Could not disable or delete the User with name [email protected] because that would have removed the last active User who is a direct member of AppRole Identity Domain Administrator."

如何将后来创建的用户设为AppRole Identity Domain Administrator，而把之前的用户删除呢？
江西网友:尴尬的十五分钟。