If it's a dent you can put a damp cloth over it and heat it with an iron to raise it up. I wouldn't recommend it for a finished guitar though, because you'll have to raise it proud and then sand it down to level to get it flat again and that would require a substantial amount of work to refinish.
If the finish is actually damaged rather than just dented then you can use runny superglue to repair it. Build it up slowly and gradually and once it's dry give it a gentle rub with some fine wire wool and a polish. If the finish is not actually split or cracked then I would just leave it.