The requirements to file a Petition for Dissolution of a Civil Union are the same as filing for Divorce, except it is between parties that participated in a Civil Union. A Petition is filed and served on your spouse personally. If their location is unknown, service can be given by publication. The parties can attempt to reach a settlement, by agreement, or can go through the process of exchanging Discovery and having the Court make a decision at Trial.
In the interim, the court can have Hearings to settle issues temporarily and/or may conduct a Pre-Trial Conference to give recommendations to the parties on how to settle their case. The final decree is called a Judgment for Dissolution of a Civil Union.