add_filter( 'register_post_type_args', 'alterar_slug_register_post_type_args', 10, 2 );
function alterar_slug_register_post_type_args( $args, $post_type ) {
if ( 'slug-atual' === $post_type ) {
$args['rewrite']['slug'] = 'nova-slug';
}
return $args;
}