Surgical scar revision is an excellent option for your forehead scar. Without surgery, subcision and fractional laser with fillers would be a good option.
I suggest you see an expert in lasers and scars. This can be improved with a combination approach. Best, Dr. Emer.
In reality, your photo shows a scar that is not that bad. It is more obvious because of the vertical orientation on your forehead, where the normal skin lines are horizontal. If it is depressed, or bothers you that much, a z-plast can re-orient the scar to a horizontal position and make it less obvious. However, scarring is difficult, and you do run the small risk or ending up with a worse scar. Be sure to consult with a board certified plastic surgeon. Check out the link below to an article I wrote about scarring, as it may be helpful. Good Luck!
These scars would be very difficult to fix. I would suggest a combination of fillers and eMatrix. Please consult an expert. Best, Dr. Green