Stand up on your toes and Lower down in a controlled fashion that's one rep either have a loaded barbell on your shoulders or if you workout with a partner have them sit on your back with your upper body slightly bent from the waist, support your hands on a bench and go up on your toes to engage calves then lower back
Stand on a step, stairs will do fine, on the ball of your feet with heel outside the step. Lower your heels as low you can go, and then push up all the way to standing on your toes. Keep the rest of your body still and avoid leaning forward. Repeat for three sets, 15-20 reps. If you're not close to crying from pain after that, you're not doing it right.