STEP 1
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Upload the contents of "upload" to your XF root directory (where index.php is located)


STEP 2
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Edit your "message_user_info" template
Admin CP > Appearance > Templates > Search for 'message_user_info' > Click 'message_user_info' to edit


find:
<div class="avatarHolder"><xen:avatar user="$user" size="m" itemprop="photo" />

add below:
			<xen:if is="{$thread.user_id} == {$user.user_id}">
			<br />
			<dl class="pairsInline">
				<dd><img src="styles/PiXhousecom/thread_starter.gif" alt="Thread starter" /></dd>
			</dl>
			</xen:if>
			
			
save it.