How to Hide High Performance CSS Slider Admin Menus

function plt_hide_high_performance_css_slider_menus() {
	//Hide the "HPCSS Slider" menu.
	remove_menu_page('edit.php?post_type=slider');
	//Hide the "HPCSS Slider → HPCSS Slider" menu.
	remove_submenu_page('edit.php?post_type=slider', 'edit.php?post_type=slider');
	//Hide the "HPCSS Slider → Add New Slide" menu.
	remove_submenu_page('edit.php?post_type=slider', 'post-new.php?post_type=slider');
}

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

Where do I put this code?