How to Hide Lktags - Linkedin Insight Tags Admin Menus

function plt_hide_lktags_linkedin_insight_tags_menus() {
	//Hide "Settings → Linkedin Insight Tag".
	remove_submenu_page('options-general.php', 'lktags');
	//Hide "Settings → Affiliation".
	remove_submenu_page('options-general.php', 'lktags-affiliation');
	//Hide "Settings → Contact Us".
	remove_submenu_page('options-general.php', 'lktags-contact');
	//Hide "Settings → Upgrade".
	remove_submenu_page('options-general.php', 'lktags-pricing');
}

add_action('admin_menu', 'plt_hide_lktags_linkedin_insight_tags_menus', 1000000000);

Where do I put this code?