I take it that you already know where to place the code. Try this:
HTML:
<div class="section visitorPanel">
<div class="secondaryContent">
<div class="visitorText">
<h3>Teamspeak</h3>
<span id="its882631"><a href="http://www.instantteamspeak.com/">teamspeak server</a> Hosting by InstantTeamSpeak.com</span><script type="text/javascript" src="http://view.light-speed.com/teamspeak3.php?IP=ts3.northland-gaming.com&PORT=10547&QUERY=9994&UID=882631&display=block&font=11px&background=transparent&server_info_background=%23D8D8D8&server_info_text=%23000000&server_name_background=transparent&server_name_text=%23000000&info_background=transparent&channel_background=transparent&channel_text=%23000000&username_background=transparent&username_text=%23FF0000"></script>
</div>
</div>
</div>
The title of the box is harcoded. You can also use a language phrase if you want. By replacing:
with:
HTML:
<h3>{xen:phrase teamspeak_title}</h3>
Then create the teamspeak_title phrase and give it whatver value you want. You can change the name of the phrase if you want as well. That was as an example.