Steps:

1. Stand next to a wall and place your hand on it for balance.
2. Take a large step forward with one leg, keeping the other leg in place.
3. Bend both knees to drop into a lunge, making an L shape with your front leg and driving the back knee toward the floor. Keep your front knee over your ankle (not beyond it) and your back leg extended behind you. 
4. Return to standing by pressing through your front foot.
5. Keep your chest and back upright and your movement smooth and steady.
6. Switch legs to repeat on the other side.
7. Do the lunge 10 times per side, 20 times in total.