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

2.Click on "Expand Widget Templates"

3.Scroll down to where you see this:

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

4.Now add below code immediately after above code.

<script type="text/javascript"> tweetmeme_url = '<data:post.url/>'; </script> <script type="text/javascript" src="http://tweetmeme.com/i/scripts/button.js"> </script>

It will look like this :

<div class='post-header-line-1'/> <script type="text/javascript"> tweetmeme_url = '<data:post.url/>'; </script> <script type="text/javascript" src="http://tweetmeme.com/i/scripts/button.js"> </script>

5.Now save your template and you are done.