Well, the best thing would be to write up all that, print it out, and put it in the same safe-deposit box that holds your will. Of all the storage media we have, paper is still the best proven for long-term retrieval.
Never, never put your will into a safe-deposit box. That cannot be opened after you die until you have an executor. Which happens after the will is found.
Just make a couple copies, leave on in your desk, in your office, in your bedside table, with your lawyer. They are not secret documents, not something you have to lock up.
