Test, 1st. If pain, stop. I assume one side pain nia, usually left. Compare with right.
Arms by side bend at elbow 90 degrees, palms face each other, open up, i.e. just move hands away from each other, pain or stuck?
Arms in air, like surrender, just one side will do. just rotate like 招财猫 but the fist goes back. pain or stuck?
Stretch, gently. bo bian. When u sleep, try to get hand to pillow or use pillow to weigh it down.
Surrender, back towards wall, raise hands up touching wall and hold it there.
Another stretch, sibei awkward, bow to a dining table or suitable height, ur elbows, both at the edge. bent elbows, try to rotate outwards. if it helps, hold a long umbrella above ur head, with both hands (it will be above ur head, L push R, stop, R push L.
Do nt use force, nt a Jedi. Find any stretch/exercises that can improve the mobility of the shoulder.