FIND THIS CODE:

Code: 
<div id="above_postlist" class="above_postlist">
		<vb:if condition="$show['largereplybutton']">
			<a href="newreply.php?{vb:raw session.sessionurl}p={vb:raw LASTPOSTID}&amp;noquote=1" 
class="newcontent_textcontrol" id="newreplylink_top"><vb:if condition="$show['closethread']"><span>+</span> {vb:rawphrase reply_to_thread}<vb:else />{vb:rawphrase closed_thread}</vb:if></a>
ADD BELOW:
Code: 
<a href="newthread.php?{vb:raw session.sessionurl}do=newthread&amp;f={vb:raw thread.forumid}" rel="nofollow" class="newcontent_textcontrol" id="newthreadlink_top"  style="margin-left:10px;"><span>+</span> {vb:rawphrase post_new_thread}</a>