I googled and found this: https://wordpress.stackexchange.com/questions/38576/is-it-possible-to-change-the-url-of-custom-post-types-to-hide-the-post-type-slug

add_action( 'init', 'create_post_type' );
function create_post_type() {
  register_post_type( 'acme_product',
      array(
          'labels' => array(
              'name' => __( 'Products' ),
              'singular_name' => __( 'Product' )
          ),
          'public' => true,
          'has_archive' => true,
          'rewrite' => array('slug' => 'products')
      )
  );
}

Could you provide a way to filter-hook this via child-theme functions.php?