How to Hide Expert HTML Section Admin Menus

function plt_hide_expert_html_section_menus() {
	//Hide the "Expert HTML" menu.
	remove_menu_page('edit.php?post_type=expert_html_section');
	//Hide the "Expert HTML → All Items" menu.
	remove_submenu_page('edit.php?post_type=expert_html_section', 'edit.php?post_type=expert_html_section');
	//Hide the "Expert HTML → Add New" menu.
	remove_submenu_page('edit.php?post_type=expert_html_section', 'post-new.php?post_type=expert_html_section');
}

add_action('admin_menu', 'plt_hide_expert_html_section_menus', 15);

Where do I put this code?