Tips on Customizing Easy PayPal & Stripe Buy Now Button

How to Hide Easy PayPal & Stripe Button Admin Menus

function plt_hide_wp_ecommerce_paypal_menus() {
	//Hide the "PayPal & Stripe" menu.
	remove_menu_page('wpecpp-settings');
	//Hide the "PayPal & Stripe → Buttons" menu.
	remove_submenu_page('wpecpp-settings', 'edit.php?post_type=wpplugin_pp_button');
	//Hide the "PayPal & Stripe → Settings" menu.
	remove_submenu_page('wpecpp-settings', 'wpecpp-settings');
}

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

Where do I put this code?

How to Hide Easy PayPal & Stripe Button Meta Boxes

function plt_hide_wp_ecommerce_paypal_metaboxes() {
	$screen = get_current_screen();
	if ( !$screen ) {
		return;
	}

	//Hide the "Button Settings" meta box.
	remove_meta_box('wpecpp_price_box', $screen->id, 'normal');
	//Hide the "Shortcode" meta box.
	remove_meta_box('wpecpp_shortcode_box', $screen->id, 'side');
	//Hide the "Save" meta box.
	remove_meta_box('wpecpp_submitdiv', $screen->id, 'side');
}

add_action('add_meta_boxes', 'plt_hide_wp_ecommerce_paypal_metaboxes', 20);