It depends on where you want to move it and how it should be integrated :)
Would you retain the layout of the forum? Should it be transferred within the directory structure of the forum, or outside?
Put your question please just a little more closely, so users here can respond more accurately.
In setup_options you find
$manualIndex='index.php?action=manual'; // or 'manual.html' for mod_rewrite
And there, with the correct entry, ... you could, for example, reach your goal. There are of course other ways ... but just depends on your exact requirements :)