Basically, we just redirect these pages to the homepage. We also disable purchasing for good measure.
if ( class_exists( 'WooCommerce' ) ) {
add_filter( 'woocommerce_is_purchasable', '__return_false' );
function disable_woo() {
if ( is_cart() || is_checkout() ) {
wp_redirect( home_url() );
exit;
}
}
add_action( 'template_redirect', 'disable_woo' );
}