Finally, that LLM you got in Zombie Law is about to pay off! The California Supreme Court ruled on Monday that wills may be amended post-mortem. That's a drastic shift from the categorical bar against modifying an unambiguous will.
Of course, those wishing to amend their wills after death won't need to reanimate a corpse or two -- though it wouldn't hurt. Clear extrinsic evidence of the testator's intent should be enough.