I have protruding forehead and I wonder what can be done to make it flat. (photo)

Changing your hair line can change the look of your forehead.  Forehead reduction or hair transplant surgery can be an option.  You would need an examination to make sure you would be a good candidate for either surgery.

There are doctors who offer surgeries that can shave the forehead. These are often plastic surgeons or maxillofacial surgeons.  

Surgery to reduce the bony prominence of a forehead such as yours is beyond the realm of cosmetic surgery. If imaging studies show a significant bony abnormality a craniofacial surgeon might be consulted. A cosmetic solution might be a hairpiece, hair transplants or surgical scalp advancement.