It’s showing at the top currently, right? If not you enable it in the Genesis Theme Settings for home page, pages, posts etc.
To get it do display at the bottom, you will need to make changes to the functions.php file. While you can do this in the admin area, you should not. Rather, you should download functions.php to your computer, make changes, then upload the file. If your site breaks, which it easily can do, you can revert your changes to the file on your computer, then upload that file to bring your site back. Otherwise, your entire site can be rendered non-functional.
So in the functions.php file on your computer using Dreamweaver, Notepad, Text Wrangler, or BB Edit (or the like) add this to the bottom to move your currently activated breadcrumbs to the bottom of your posts and pages:
//* Do NOT include the opening php tag
//* Reposition the breadcrumbs
remove_action( ‘genesis_before_loop’, ‘genesis_do_breadcrumbs’ );
add_action( ‘genesis_after_loop’, ‘genesis_do_breadcrumbs’ );