If it’s just a menu that will stay forever (even not it’s ok as update is super easy), don’t think too complicated, just copy the menu code (from browser > view source) and paste it to Magento template file. Logical choice is ’header.phtml’, but you can also create a Static Block with this code place in "header.phtml"
<?php echo $this->getLayout()->createBlock('cms/block')->setBlockId('your_wayfinder_menu')->toHtml() ?>
Then from Magento admin, create a static block with "your_wayfinder_menu" as identifier, place the menu code in the content area. If you don’t want the menu shows up in certain pages, you can use XML update to overwrite it.
Hope this helps!