Wordpress header and footer into a PHP site

I practically have a working sub-directory folder webpage. I would like to have the wordpress header 开发者_StackOverflow社区in the page.how can I do this?

example:

main-site/ a wordpress site: butternjam.com site that I would like to have wordpress header and footer. : butternjam.com/directory

the files in there are php files how can I implement my wordpress header and footer into this page?

<?php get_header(); ?>
<?php get_footer(); ?>

Make sure that the header and footer are called header.php and footer.php