If you've been through a divorce, but need to modify an agreement, contact the San Diego Post-Divorce modification attorney at Embry Family Law P.C. today! The San Diego Divorce Attorney can assist you with the modification process from the filing process and if required, represent your case in a court of law.In California, divorce modification is possible, but only certain parts of the divorce decree can be changed. In any divorce case the agreements between the parties are set forth in a Marital Settlement Agreement. Learn more about this Agreement. Both parties must complete and file with the court a Child Support Case Registry Form (form. FL-191) within 10 days of the date of this order. Modifying a court order after it has been made is a difficult process. Learn how to modify child custody in California, including the requirements, process, and forms necessary, and where to find cheap, professional help. First, it's important to note that not every provision in a decree of divorce can be modified.