How to Hide Portfolio Responsive Gallery Admin Menus

function plt_hide_portfolio_responsive_gallery_menus() {
	//Hide "Settings → Portfolio Responsive Gallery".
	remove_submenu_page('options-general.php', 'portfolio-responsive-gallery');

	//Hide "Portfolio Responsive Gallery".
	remove_menu_page('portfolio-responsive-gallery');
	//Hide "Portfolio Responsive Gallery → Portfolios".
	remove_submenu_page('portfolio-responsive-gallery', 'portfolio-responsive-gallery');
	//Hide "Portfolio Responsive Gallery → Attributes".
	remove_submenu_page('portfolio-responsive-gallery', 'portfolio-responsive-gallery-portfolio-attributes');
	//Hide "Portfolio Responsive Gallery → How to use".
	remove_submenu_page('portfolio-responsive-gallery', 'portfolio-responsive-gallery-portfolio-how_to_use');
}

add_action('admin_menu', 'plt_hide_portfolio_responsive_gallery_menus', 11);
Where do I put this code?