Sit erect on the floor with legs extended in front of you, knees bent slightly. Hold a medicine ball or anything that weighs about 5-8lbs. Look around your house you will find something i.e. a dumbbell, a small water jug. Hold it close to your middle, elbows bent close to sides. Slowly rotate to your left, as if to set the ball just behind your left hip; follow the ball with your eyes, allowing your upper torso to rotate. Repeat, this time rotating to your right side; continue alternating sides. Start with 2 sets of 12 to 20 reps.
Add a third set if you can, resting 1 minute between sets.
Good Luck and leave a comment with any questions that you might have. I would be glad to help.