Stand with your feet shoulder width apart, toes pointed forward. Hold medicine ball out in front of your body, slightly above your chest, with arms straight. Do not lock your elbows.
Lower your body, bending at the hips, keeping your weight back on your heels. Keep your back as upright as possible. Make sure your knees don’t cross the plain of your toes. Don’t go past 90 degrees at your knees.
You can progress by raising the weight of the medicine ball. If you do not have a medicine ball you can also hold a compact object of similar weight (2-10 lbs. depending on strength) out in front of you
See video here.