ex holding up pension

State, California, my divorce settlement states I will 38.8% of my ex-husband’s union pension upon his retirement. The QUDRO states my portion will be paid based on his life span. To have the pay based on my life span, the union needs an amendment to the QUDRO. I have had the amended QUDRO written up and the union has accepted the wording. Now I just need to file and have a Judges’ signature. Do the amended papers have to have the ex-husband’s signature? The amended QUDRO does not affect him in any way, and he is already receiving his pension. The amendment only changes how I will be paid. Is there anyway I can file and have a Judge sign the papers without the ex-husbands signature or can the papers be written up without a signature line for my ex because he refuses to sign. If my ex-husband does not sign, it leaves me only to collect based on his life span not mine. Please help---this is my future he is messing with.