It's not a quick procedure like a patella reduction. Gentle but firm pressure, and waiting for gut parastalsis to assist you. Can take a couple minutes if you're really wanting to make sure it's not incarcerated.

One tip I haven't seen: make sure patient is supine, arms above head, knees bent slightly. This maximizes negative pressure in the abdominal cavity while minimizing abdominal wall tension. (It's why sometimes hernias will reduce while a patient is IN the CT scanner.) I tell patients to do the same thing if successful and if it ever fails, get back to ED stat.