Is it caused by weakness in a specific part of the shoulder musculature or what? If that's the case, just strengthening the muscles with side raises, front raises, overhead presses, Cuban presses, 'innies' and 'outies' etc. with band resistance could do the job.
I'd recommend consulting a physician who works with athletes. They tend to know their way around correcting stuff like this through exercising better than regular physicians without sports background or involvement.