Interesting. The short answer would be "Jehova's witnesses don't know how the members of the Govening Body are elected".
I know that these days there are some members of the GB who are not of the anointed, but let's go back and think about the time when they were all anointed. It's always YOU who tells the world that you're one of that "class".
It would be even more interesting to know how you become a member of the board of the corporations. That should be available in a public instrument, right?