If both-side agree to separate

I don't think u need a lawyer. Try to find a legal 協議離婚form and copy it. A lot of legal docuaments are in certain forms. You need a witness to co-sign it. You only need a lawyer when both of you are disagree on certain things, such as who will live with the child and how much the child-support will be. If you both agree with everything, it should be very simple. I don't think you need 需要提訴. 需要先分居. 需要證明有人調節無效. These are all my thinking. Anyone who went through all these please share you experience with us please. I am on the same path too, not go that far yet.