From Ground: First, water the low mallow plant thoroughly to make the soil easier to handle. Take your spade or trowel and dig a wide circumference around the base of the plant, ensuring you're going deep enough to keep as many roots intact as possible. Keep the root ball together as much as you can, and carefully lift the plant from the ground. Use a wheelbarrow if needed to move the plant to its new location.
From Pot: If the low mallow is in a pot, make sure the soil is moist and carefully tip the pot upside down while supporting the plant. Gently tap the bottom of the pot if the plant doesn't slide out. Handle the plant by its root ball, not the stem or leaves.
From Seedling Tray: If your low mallow is still a seedling in a tray, water it first to make removal easier. Then gently ease the seedling out of the tray by pushing up from the bottom, taking care to preserve as much of the root system as possible.