Tips on Customizing ML Responsive Audio player with playlist Shortcode

How to Hide MLR Audio Admin Menus

function plt_hide_mlr_audio_menus() {
	//Hide "Settings → MLR Audio".
	remove_submenu_page('options-general.php', 'mlag');

	//Hide "Audio Elements".
	remove_menu_page('edit.php?post_type=ml_audio');
	//Hide "Audio Elements → Audio Elements".
	remove_submenu_page('edit.php?post_type=ml_audio', 'edit.php?post_type=ml_audio');
	//Hide "Audio Elements → Add New Audio Element".
	remove_submenu_page('edit.php?post_type=ml_audio', 'post-new.php?post_type=ml_audio');
	//Hide "Audio Elements → Audio Category".
	remove_submenu_page('edit.php?post_type=ml_audio', 'edit-tags.php?taxonomy=audio_category&post_type=ml_audio');
}

add_action('admin_menu', 'plt_hide_mlr_audio_menus', 11);

Where do I put this code?

How to Hide MLR Audio Meta Boxes

function plt_hide_mlr_audio_metaboxes() {
	$screen = get_current_screen();
	if ( !$screen ) {
		return;
	}

	//Hide the "Audio parameters" meta box.
	remove_meta_box('track-meta-box-id', $screen->id, 'normal');
	//Hide the "Single Audio Shortcode" meta box.
	remove_meta_box('unique-meta-box-id', $screen->id, 'side');
}

add_action('add_meta_boxes', 'plt_hide_mlr_audio_metaboxes', 20);