4 yr. Ago I had hemorrhoid surgery. Now I have an hemorrhoid in the same place, is there anything I can to AT HOME to make it shrink back to normal?

Yes. It depends on the size and degree of hemorrhoids. Smaller ones will respond to treatment. Witch-hazel wipes or preparation H can reduce size and symptoms as will warm baths. Most importantly is avoiding making them worse. A high fiber diet with fiber supplementation, ensure lots of water intake, avoid excessive strainig with bowel movements.
Yes. There are many over the counter hemorrhoid ointments that contain a steroid and another medication to help constrict the blood vessels and reduce the inflammation. Just go to your local pharmacy and the pharmacist can point out your options. Don't forget to take a stool softener, eat plenty of fiber and drink plenty of water.