Although both are usually translated to "lie this", they mean different things. - 이대로 = 이(this) + 대로 (the way it is) = leaving it the way it is now without changing or adding to it. - 이렇게 = 이러하게 = (in) this way/method. So 이대로 implies there's an existing state and you keep it as is, while 이렇게 presents a new way or manner. 이렇게 can also be an intensifier for an adjective, as in 사람이 이렇게 많다 (There are THIS/SO many people). - 일도 안 끝내고 이대로 가면 어떡해? = How can you just leave like this without finishing the work? (implies something needs to be done but they are taking off leaving it the way it is). - 이 기계를 작동시키려면 이렇게 하세요 = Do this (Do it like this) to operate this machine.