Please always include what version of osTickets you are using, I'd hate to duplicate my work looking for one version and then the code not being where you expected it to be ;)
For now since you only have a few posts I shall assume you are on 1.6ST. In that case, both of these are untested but should do the trick:
Removing Knowledge Base and Directory tabs:
include/class.nav.php
Remove or comment out the following lines
if($thisuser && $thisuser->canManageKb()){
$tabs=array('desc'=>'Knowledge Base','href'=>'kb.php','title'=>'Knowledge Base: Premade');
}
$tabs=array('desc'=>'Directory','href'=>'directory.php','title'=>'Staff Directory');
index.php
Remove or comment out the following lines:
<div class="rcol">
<img src="./images/ticket_status_icon.jpg" width="48" height="48" align="left" style="padding-bottom;">
<h3>Check Ticket Status</h3>We provide archives and history of all your support requests complete with responses.
<br /><br />
<form class="status_form" action="login.php" method="post">
<fieldset>
<label>Email:</label>
<input type="text" name="lemail">
</fieldset>
<fieldset>
<label>Ticket#:</label>
<input type="text" name="lticket">
</fieldset>
<fieldset>
<label> </label>
<input type="submit" class="button2" value="Check Status">
</fieldset>
</form>
</div>
