How to Hide the "SelfAssemblySites Website Video User Guide" Dashboard Widget

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

	//Remove the "SelfAssemblySites Website Video User Guide" widget.
	remove_meta_box('sas_dashboard_widget', 'dashboard', 'normal');
}

add_action('wp_dashboard_setup', 'plt_hide_sas_wp_video_user_guide_dashboard_widgets', 20);

Where do I put this code?