Here is a spoiler for you: clearing stuff from someone who died, might take a year or more and lots of money. From unlocking the cellphone, to enter the email, bank accounts and inheritance, it IS a big deal.
So better deal with it before than after. What should go into this file? Examples are marriage certificates, funeral instructions, letter to your loved ones, an inheritance certificate, and passwords for all your media and accounts. It is an act of love, maybe your final one.