1) Place a weighted plate on the ground, or something that would provide the same level of elevation.
2) Hold a pair of dumbbells next to your body with your palms facing your body. Or place a barbell resting on your traps.
3) Step on the weighted plate with your toes on top of it while your heels are touching the ground. Keep your feet relatively close to each other.
4) Raise your heels off the floor and squeeze your calves.
5) Slowly lower yourself back to your starting position.