Begin in a seated position with both feet on the floor, and then bring the right foot up so that the right ankle is resting on top of the left thigh.
With both hands grasp the right lower leg (tibia) from above at the ankle and near the knee until the lower leg is pulled/stretched in a medial direction (towards you) with both hands. In this position your foot will point towards the ceiling.
Once you have rotated the lower leg inwards as far as comfortable, use your leg muscles to hold this position and let go with your hands. Maintain the position with active contraction of your leg muscles.