Add non-wordpress header menu to my wordpress site?

Hi there.
I’m using storefront theme for my woocommerce store;

I’ve cut out my theme’s header menu, and footer text, so that I only get the products section of the page. (As you can see here: https://bit.ly/1qfo0R4 )

My question is, I would like to lift the header menu from my current non-wordpress website ( bit.ly/1MQMeGb ) , and somehow implement it into my wordpress shop page.

Does anyone have any ideas about how they might do this?

Many thanks in advance.