Hold a low pulley handle in one hand. Stand on one leg, on the same side that you hold the handle
Keeping that knee slightly bent, perform a stiff legged deadlift by bending at the hip, extending your free leg behind you for balance and extending your arm and handle forward. You should feel a stretch through the hamstrings
Continue extending the handle until you are parallel to the ground, and then return to the upright position.
Repeat this motion for the recommended number of repetitions on both sides.