All afaik:
- The order is declared unconstitutional in a court challenge (this obviously takes time and could go up to the Supreme Court)
- Congress takes action by passing a bill reversing the order or something along that line (you wish, lol)
- The incumbent president repeals the order (obviously, we'd need a different president for that first...).
Can someone come up with a bill on monday and have congress vote on it within days?