What is the process for PF pension share withdrawal, incase pension holder dies before 60?

Sorry if the flair is wrong, but that's the one closest I found. Anyways as per the title, my dad withdrew all EPFO when retired from job to consultant and the pension amount in EPFO can't be withdrawn. So, now he is no more and wanted to know the process for the withdrawal towards my mom for the amount. Even the new UAN only has last company PF records, previous old companies I found a PF no. But no UAN and dnn which old number was registered. If anyone has any knowledge in EPFO in these situations please shed some light. Tried know your UAN but gives latest UAN only.