How to Hide SendPress Newsletters Admin Menus

function plt_hide_sendpress_menus() {
	//Hide "Appearance → Email Templates".
	remove_submenu_page('themes.php', 'customize.php?url=http%3A%2F%2F127.0.0.1%2F%3Fsendpress_display%3Dtrue%26spemail%3D0&sendpress_display=true&spemail=0');

	//Hide "SendPress".
	remove_menu_page('sp-overview');
	//Hide "SendPress → Overview".
	remove_submenu_page('sp-overview', 'sp-overview');
	//Hide "SendPress → Emails".
	remove_submenu_page('sp-overview', 'sp-emails');
	//Hide "SendPress → Reports".
	remove_submenu_page('sp-overview', 'sp-reports');
	//Hide "SendPress → Subscribers".
	remove_submenu_page('sp-overview', 'sp-subscribers');
	//Hide "SendPress → Queue".
	remove_submenu_page('sp-overview', 'sp-queue');
	//Hide "SendPress → Settings".
	remove_submenu_page('sp-overview', 'sp-settings');
	//Hide "SendPress → Help".
	remove_submenu_page('sp-overview', 'sp-help');
	//Hide "SendPress → Pro".
	remove_submenu_page('sp-overview', 'sp-pro');
}

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

Where do I put this code?