Ask HN: Multi-Key Text Decryption

Here’s the problem: I want to disclose all my financial details (accounts and passwords) to my family members (spouse, children, parents and siblings) in case of sudden death. I want everyone to have a little piece of the puzzle such that when everyone agrees to share their piece, only then the encrypted text with all the secrets is revealed. My family isn’t too tech savvy. What’s the safest and simplest solution to go about it?