Disowning Family Members

Wow oh wow. I drive past that place daily. At least once, sometimes twice depending on which way I go. Sad to hear.
I have heard the team "I disowned (someone)" many times, I thought that was just a way of say I don't talk to them no more, want nothing to do with them, didn't know there was actually any official laws or legal process along those lines...
The closest thing I know of is "writing them out of any will or trust" but unfortunately you're still related by blood ....