From Ground: Start by watering the devil's tobacco plant enough to dampen its surrounding soil. Use a spade or shovel and dig a wide trench around the plant, making sure you leave enough room to keep the root ball intact. Work the spade or shovel under the root ball and carefully lift up the plant to remove it from its original location.
From Pot: Water the plant lightly to just moisten the soil. Turn the pot sideways and tap its edges to loosen the soil. You can lightly pull the devil's tobacco up by the base of its stem to pull it out. If the plant is still stuck, then you might need to use more force or cut the pot away.
From Seedling Tray: Water the seedling tray, then use a small gardening tool or your fingers to gently prise out the seedling from its slot. Be careful to grasp the devil's tobacco by its leaves, as the stem is very fragile at this stage.