Lie on tall bench with thigh hanging down off end or side of bench. Raise opposite thigh toward side of torso. Hook hand around inside of upper thigh. Grasp elbow with opposite hand and keep arms close to body.
Allow lower thigh to drop toward floor. Hold stretch. Repeat with opposite side.
Alternatively, both hands can anchor upper thigh, on hand inside and other on out side of thigh. The leg may also hang from side of bench if body is positioned slightly diagonal. If stretch is not felt, pull upper thigh closer to side of torso with both hands or use taller bench if heal touches floor.
Other (see comment)