You may change your own display name and personal headshot for your blog(s) in the Authors page.
To add additional authors who can post to the blog, you need to set them up as an Admin User. Their admin account needs permission to access the Blog Manager. For more information on adding admin users, see Administrative Users.
To change the author's name and photo as they appear on the blog, click the name that is currently there and type in the name that you want. Add a photo from the list of images in the drop-own menu.