How to Move Ownership of Your NAS

For me at the moment if I died there's just going to be a bunch of servers and stuff sitting in the garage and a couple of laptops that no one has any credentials for. Recently I've been trying to get some accounts at least shared access you know I've got a bit more than family accounts so I can share stuff with my family though I haven't actually explained how to use most of it. Trying to move ownership of things like my brother's phone bill to him instead of me owning it he paying it. That's a long story. He was using my gondi email which well that went out the window so he is now on fast mail and we both have control over