Login to your self-hosted wordpress blog -> Appearance -> Editor
Single.php -> add the following code where you want it to appear: <a title="Post to Google Buzz" href="http://www.google.com/buzz/post" data-button-style="normal-count"></a>
<script type="text/javascript" src="http://www.google.com/buzz/api/button.js"></script>
Click Update File. Done.
II. Using Google Buzz Button Plugins
After login to your self-hosted wordpress blog -> Plugins -> Add New
Search for “Google Buzz Button For WordPress” -> click Search Plugins / or Download it from here.
Click Install -> Activate and follow the setting guide.