Bless his heart....my model is trying, you have to give him that!
Step out into a wide squat with knees bent and feet pointed out...think ballet. (sorry, my model said he couldn't do that :) Be sure that your knees don't go over and out past your toes.
Raise your right arm up over your head and reach as far to the left as you can keeping your body straight (poor model!) Bring your arm back down slowly and repeat on the other side. Repeat this side to side motion for 60 seconds keeping good form.
If you have a bad knee, like me, and can't squat low, just go as far as you can without making your knees hurt. The important part is the overhead stretch.