How to change the Author on a Blog/Post Page?
1.) Go to Blog -> Blog Posts
Select Blog from the left hand menu of your Dashboard.
2.) Find the Blog Post you want to change.
Use the Search Box in top left of the list to find the Post.
3.) Mouse over the Blog Post Name and Select -> Quick Edit
This will bring up a settings menu where you can change various information about the Post.
4.) Change the Author.
Select the Account that you would like to show as the Author of this Blog.