Sterilite tub with lid *weight on tub if needed to guarantee snake stays in tub*
1 to 1 1/2 inches of 85 degree water
a towel in the bottom will cover most of the water and allow the snake to lay on it.
I also add a half log hide for the snake to use to assist rubbing off the old shed.
I usually soak 30 minutes and see if the shed comes off easily, if not I replace with 85 degree water and soak for 30 more minutes.
After the soak the shed should slide off fairly easily if it's not already off.