How to Hide Dashboard Instruction Guide Admin Menus

function plt_hide_dashboard_instruction_guide_menus() {
	//Hide the "Dashboard Instruction Guide" menu.
	remove_menu_page('dashboard-instruction-guide');
	//Hide the "Dashboard Instruction Guide → Dashboard Instruction Guide" menu.
	remove_submenu_page('dashboard-instruction-guide', 'dashboard-instruction-guide');
	//Hide the "Dashboard Instruction Guide → All Instructions" menu.
	remove_submenu_page('dashboard-instruction-guide', 'all-instruction');
}

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

Where do I put this code?