A direct translation would be 이걸/이렇게 해 주시면 정말 고맙겠어요, but we more often state the thing we need than say 이걸 (this) or 이렇게 (this way). e.g. - 청소를 도와주시면 정말/너무나 고맙겠어요 = I'd really appreciate it if you help me with cleaning it up. - 부탁을 하나 들어주시면 정말 고맙겠어요 = I'd really appreciate it if you could do me a favor.