California: My cousin recently past, and had a revocable trust naming me as the trustee and beneficiary of the trust. He also named me the executor and the his contingent beneficiary in his will to all of his assets. He set this up in 2008 due to his failing health. He forgot to change the name of the beneficiary on his 401k plan that is included in the trust. It is in his mother's name. Now, I don't have any liquid asset to finish up his business because of this mistake. The trust even states I'm to get everything listed in the trust. I'm aware that the trust is irrevocable now. It doesn't make sense set this up and not change the designated beneficiary named on the 401k, which is now the estate due to tax issues, hence the reason why he set this up to protect his assets. Can someone help with this issue?