Get a resistance band from any sporting goods store...smaller band with less resistance. Anchor it to something like a door. Increase resistance by stepping further from the anchor point.
Below is a video. I'd start out with the medial and lateral exercises until you gain some strength back in your rotator cuffs. Rep until you feel like your rotator cuff starts to fatigue/burn. get blood flowing in the area. Keep it controlled and slow.
I do these twice a day when I get injured. Within a few days the pain goes away. I kept doing them ever so often and I also get less injuries with a stronger rc.
There should be no extreme sharp pains or popping when you do these..if so adjust your angles or lessen resistance. If you still can't rep with out sharp pains don't try them see a physical therapist.
https://youtu.be/EY2tNBOmvGs
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