gistfile1.txt

I have this HTML fragment from a vBulleting board:
<div id="post_message_5344600">
<div style="margin: 5px 20px 20px;">
 <div style="margin-bottom: 2px;" class="smallfont">Quote:</div>
   <table width="100%" cellspacing="0" cellpadding="8" border="0">
   <tbody><tr>
       <td style="border: 1px inset;" class="alt2">
         <div>
           Quote from <strong>Ahnungslos</strong>
           <a rel="nofollow" href="showthread.php?
p=5344371#post5344371">Show post</a>
         </div>
         <div style="font-style: italic;">Some text<br>
           <br>
           tss tss...
         </div>
       </td>
     </tr>
    </tbody>
 </table>
</div>

Some other text
</div>

That I would like to convert back to its original BBCode style:
It should look like this:
[QUOTE=Ahnungslos;5344371]
Some Text

tss tss
[/QUOTE]

Some other text


Basically its an XSLT transformation, but I have no idea how to do
that in nokogiri.
This first DIV (div style="margin: 5px 20px 20px;) marks the start of
the [QUOTE] part of BBCode.
The first DIV inside the table contains the username between the
strong tags.
The next DIV (div style="font-style: italic;") contains the actual
quoted text, that is everything between the [QUOTE][/QUOTE] tags in
BBCode.
The follows the message text that is not part of the quote.