1.Log in to your dashboard--> layout- -> Edit HTML

2.Click on "Expand Widget Templates"

3.Scroll down to where you see this:

<span class='post-author vcard'>
<b:if cond='data:top.showAuthor'>
<data:top.authorLabel/>
<span class='fn'><data:post.author/></span>
</b:if>
</span>

4.CUT above code and paste it just after,

<div class='post-header-line-1'/>

or

just before,

<data:post.body/>

5.Click on "Save Templates" and refresh your site.