Start by placing your hands on your hips and placing your left leg forward and lowering yourself down so that you left leg’s thigh is parallel with the ground and so that the angle between your thigh and calf, at the knee is 90 degrees.
While doing this lower your right knee to just about an inch off the ground (so that your right thigh is perpendicular to the ground). As in the picture below.
Now from this position thrust yourself upwards off the ground, and while in the air you change your stance by bringing your left leg backwards and putting your right leg forwards. You then land on this opposite stance, and then thrust yourself again off the ground switching legs once again and landing as you did at the beginning. Now that is one rep. The whole exercise is a continuous movement and you keep going until you have finished your specific amount of repetitions.