Best way to make a big muscle neck smaller/thinner? (good chin projection, 24 years old 8% body fat)

Dear doctors, I am a 24 year old person that always had a big neck. With blouses i can´t close the top buttom. I have only 8% bodyfat but still bad jawline and neck goes almost into chin. While projection of the chin is good. Are there possibility´s to make the neck smaller ? Thank you