The easiest way to start is by callling the administrator of your 401k plan and asking. Some 401(k) plans require only a copy of the court order (divorce judgment) that sets out what amount is supposed to be transferred. If a QDRO is required, the administrator may be able to send you a sample form and instructions, but it's very easy to make mistakes in completing them which can result in unintended financial loss to one party and unintended financial gain to the other. Obviously, your safest bet would be to contact a family law attorney for assistance.
Answered on Jan 18th, 2016 at 1:05 PM