Is Brow Bone Reduction Difficult?

Any well-trained, board-certified (American Board of Plastic Surgery) plastic surgeon can do brow bone reduction using basic techniques. I do this in my AAAASF-accredited office surgical facility as an outpatient operation that takes about an hour.

In contrast to other answers, I would use neither an endoscopic nor a hairline-incision approach--the former does not give enough visible access to accurately assess the amount of bone that can be safely removed without (inadvertently) entering the frontal sinuses; the latter yields a visible scar (however fine and minimally-visible) at a hairline that may not always be there! Rather, a bi-coronal incision near the top of the head that lies in the "watershed" area of the frontal sensory nerves and the posterior sensory nerves yields optimal exposure, an invisible scar even if your hairline recedes in a few years, and clear access to perform bone burring with standard bone tools. I do this for patients like you who wish to reduce the "frontal bossing" or "Neanderthal" look, and for male to female transgender patients who wish this area softened and less hyper-masculine.

An intraoral incision cannot be used to access this area (by anyone of any specialty), and you should be able to achieve results close to the simulated image you provided. Seek a PS with some craniofacial training or extensive facial fracture experience. This is "not a big deal" for someone with these credentials!

Brow bone reduction is a relatively straightforward procedure. First x-rays are taken to determine the extent of your frontal sinuses. 15% of the population have a frontal sinus only on one side and 5% have none at all!An incision going over the top of your head (coronal incision) is made to develop a flap which is elevated down to the level of the brow bone. The bone is the drilled down. In some cases, with a very extensive frontal sinus, it is necessary to push the front wall of the sinus inward. However, this is quite unusual as most people get a great result with just the burring down of the bone. Additionally, if a patient is interested in creating more of a vertical or slightly rounded forehead rather than a posteriorly sloping one, it can be built up with a synthetic material called methylmethacrylate. 

A forehead shaving could be acheived using an endoscopic approach and a hair line incision. The limit to perform this procedure is the thickness of the bony portion of the sinuses(air cells) located in the front portion of the forehead(the frontal sinus).The computer imaging you attached could be unrealistic but this could only be confirmed with an imaging study to measure bone thickness. Best of luck!