Hammer and dilly yes, kind of. I would use a hammer with a crown that curves the same direction as the fender radius. Hold the fender chrome side (outside) pressed to the bench on a leather or hard rubber pad, to do as little damage to the chrome as possible. Basically using the padded bench as the dolly, all hammering off dolly until you see how the metal is moving.
Start working the dent inside to outside, light taps, take your time.