Very tough problem

The reason for little information is that dark skin individuals are very difficult to treat with lasers. There are some lasers which can be safely used on darker skinned individuals. What you describe though may not be best treated with a laser but may be best treated with other modalities such as dermabrasion or serial excisions of the scar to make it less noticeable. I would suggest visiting with a plastic surgeon or facial plastic surgeon to determine your best course of action. Best of luck.