I would kindly ask your doctor to do a little better job of explaining himself on the excercises that he wants you to do. Coming out of surgery and then being asked to start doing exercises with no direction is trouble waiting to happen. You can even have your trainer speak with the doctor directly. I have done that many times with my post operation clients. This will ensure that you are off to the right place.

As with most surgery, it is important to start off slowly and work on control and Range of Motion (ROM).
Since your doctor did not specify I am going to assume you are free to do most conventional exercises.
A good start would be to incorporate 2-3 exercises that will have you in some flexion (chin to chest), some extension (chin up)as well as rotation (moving your head left to right). Resistance can be as simple as pushing into your hands. As this becomes less of a challenge start doing regular exercises like shrugs, shoulder presses and upright rows with moderate weight.

Best of Luck,

George Tabares Fit. Spec./MT