How do I control what the author name is on my posts?

I am in the middle of a legal name change; my new social security card just arrived today. My credit card is still associated with my old name. Because of this, my old name is displayed on all of the posts I make, despite the fact that I created the site under my new name. How do I control the author name on my posts?

You can make a new account with permissions to your blog, with your new name
And then manually change all posts’ author in the posts’ settings


Update: the display name on my blog entries is now correct.