We see the occasional query, about name changes, in Blogger Help Forum: Learn More About Blogger . I just got married, and now I have a new email address, and a new name. How do I change my Blogger identity? And the usual advice was You can change youe email address, and / or change the display name (not the account name) - and you can transfer control of the blog to a new Blogger account, which bears your new name. But old posts will remain, with your old name. And there, we would have one more disappointed blog owner. But that does not have to be the final answer.
What Blogger won't tell you