There is no way to take anything like that. Net worth is quite similar with me saying you are worth 1 billion dollars, but you have zero money in the bank. What do you take, super-rich billionaire person?
In the rare cases where contract law makes the transfer impossible legally the government could trivially step in to make it possible
Is it Zuck's networth or salary that makes it possible for him to own his ranch in Hawaii?
whats the complication? if its not worth anything whos gonna worry, especially if the government then compensates you in dollars
And certainly ceejayoz was being a bit glib by suggesting we take all of it, but it would not be remotely insurmountable to tax billionaire wealth.
This is, ironically, more of a guess/estimate than determining Musk's net worth is. We don't actually know that!