Why? Removing a scar is not possible. You simply replace it with a new one. Why do you ask?If the scar causes pain with erection perhaps you need to open up the scar and place a skin graft. If your penis is crooked then perhaps the problem is below the surface and there are treatments for that. If everything's working ok and you don't like the way it looks you should consider leaving it alone.
It depends. If the scar is less than six months old, it may remodel so much with the body's natural healing that it becomes nearly invisible. But if it's older than 6-12 months, then it is probably worth it to consult with a plastic surgeon. Scars can never be removed completely once you have them but a good surgeon has techniques to lessen many of them.