How to Hide Grid Kit Admin Menus

function plt_hide_portfolio_wp_menus() {
	//Hide "Grid Kit".
	remove_menu_page('grid-kit');
	//Hide "Grid Kit → Portfolios".
	remove_submenu_page('grid-kit', 'grid-kit');
	//Hide "Grid Kit → Albums".
	remove_submenu_page('grid-kit', 'grid-kit-albums');
	//Hide "Grid Kit → Galleries".
	remove_submenu_page('grid-kit', 'grid-kit-galleries');
	//Hide "Grid Kit → Client logos".
	remove_submenu_page('grid-kit', 'grid-kit-client-logos');
	//Hide "Grid Kit → Teams".
	remove_submenu_page('grid-kit', 'grid-kit-teams');
	//Hide "Grid Kit → Product catalogs".
	remove_submenu_page('grid-kit', 'grid-kit-catalogs');
	//Hide "Grid Kit → Sliders".
	remove_submenu_page('grid-kit', 'grid-kit-sliders');
}

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

Where do I put this code?