-기만 하면 되다 is an expression used to indicate that, as long as one performs a certain action, there is no problem or it is enough.
어요 is a polite ending used in informal polite speech.
체셔 고양이: “오, 넌 분명히 갈 곳이 있을 거야,” 고양이가 말했다, “오래 걷기만 하면 돼.”1 Cheshire Cat: “Oh, you’re sure to find a place,’ said the cat, ‘as long as you walk long enough.”