Need to change author's name in blog post

Need to change author's name in blog post

My colleague wrote a blog post for our blog but when I put it on our site, the author's name automatically populated as mine. I contacted ZohoSupport and was told to change the Nickname in my profile. Well, I did and then ALL the blog posts were listed as being written by my colleague! Is there any way to simply change one blog post with the correct author's name?