Thanks for the heads up guys and I figured it out since, the plugin doesn't work with the latest version btw so its useless anyways. Instead I did it manually;
Edit Postbit_classic (I use classic I hate the other style):
And in the same row where reply buttons are and the date on left I made these changes:
<table width="100%" border="0" cellpadding="0" cellspacing="0">
<tr >
<td align="left" ><span class="smalltext"><!-- AddThis Button BEGIN -->
<div class="addthis_toolbox addthis_default_style addthis_16x16_style">
<a class="addthis_button_facebook">
<a class="addthis_button_twitter"></a>
<a class="addthis_button_email"
<a class="addthis_button_google_plusone" g:plusone:annotation="none"></a>
<a class="addthis_button_more">
<a class="addthis_counter addthis_bubble_style"></a>
</div>
<script type="text/javascript">var addthis_config = {"data_track_addressbar":true};</script>
<script type="text/javascript" src="//s7.addthis.com/js/300/addthis_widget.js#pubid=YOURID"></script>
<!-- AddThis Button END --></span></td>
<td align="right">{$post['button_edit']}{$post['button_quickdelete']}{$post['button_quote']}{$post['button_multiquote']}{$post['button_report']}{$post['button_warn']}{$post['button_reply_pm']}{$post['button_replyall_pm']}{$post['button_forward_pm']}{$post['button_delete_pm']}</td>
</tr>
Just place your addthis profile user ID in the YOURID spot.
I removed the align bottom in the table as the reply buttons and the date and the addthis buttons were not aligning. Looks better like this.
You can further customize the addthis buttons and add more or remove some... and customize the appearance (use different images)
by going to addthis.com and reading up on their customization API