I would suggest you start with the passive stick exercise and add one additional exercise each day hopefully building up to the whole program at the end of the month. Check in how that feels and give your body a day to say yes or no to that exercise. Take the time to listen to the response and give yourself an opportunity to integrate the movement and the new postural placement .  With tendon injuries they can be slow to recover and grading your load is important.  If in doubt show your manual therapist and check that this is appropriate for you.  

A donor tendon, screws and anchors were used as my infraspinatus wouldn't stretch back. I feel like I have a mass of scar tissue restricting my movement with no external rotation.

I'm hoping that these exercises are going to free me up so I can work on the external rotation.

Thank you so much