If thats all you want, after you update go to AdminCP ->Styles and Templates -> Style Manager -> Member Info Templates -> MEMBERINFO
In that template find
HTML Code:
<div id="profile_tabs">
$template_hook[profile_left_first]
$blocks[visitor_messaging]
$blocks[aboutme]
$blocks[stats]
$blocks[friends]
$blocks[infractions]
$blocks[contactinfo]
$template_hook[profile_left_last]
</div>
Right below that will be this code....
HTML Code:
<script type="text/javascript">
<!--
vBulletin.register_control("vB_TabCtrl", "profile_tabs", "$selected_tab", "»", "profile.php?u=2&do=loadtab&tabid={1:tabid}");
//-->
</script>
^Delete that and it will not show up as tabs anymore... But to warn you its pretty ugly that way to. If you do not want tabs I would look at some of the changes made in some of the Myspace/Facebook mods and try to create a better looking profile.