The code snippets below should be pasted into your child theme's functions.php file.
Here is how you can deregister the primary sidebar. This will remove the primary sidebar widget area as well as the appropriate layout options in the admin.
// Remove the primary sidebar.
add_action( 'widgets_init', 'example_widget_area' );
function example_widget_area() {
beans_deregister_widget_area( 'sidebar_primary' );
}