Average Joe should stay away against lawyer or someone who understand about laws. If the lawyer steal the coins, the Average Joe has no way to sue them because the lawyer already know what they can do and what not. If Average Joe insist to sue them, they might go to jail, imagine you lost your coins and now you lost your time.
Sometimes, even you win the case, you high likely won't get back your assets.
Except if you are too rich and have too many bitcoins, I see no big reason of hiring lawyers for this task.
You can store, secure your bitcoin by yourself because with Bitcoin, it's easily to have Bitcoin private keys, mnemonic seeds, and it's always your bitcoins and your Bitcoin wallet backups.
You can do all necessary steps by yourself very safely and offline. You can leave information necessary for wallet backups and recovery later, to people you trust, love and want them to inherit your bitcoin.
Lawyers can be hired in case you are too rich and have very big fortune to leave for someone else.