michael jackson, - I would normally just give the advice to just log on and close the [[6000000016650216263 ]] account and all profiles will be automatically deleted since we are talking about a unconnected/stand-alone tree (- i.e. not the world family tree, usually called "the big tree")
I do however observe that there are two more recently logged in users in that tree, Private User and Private, so they have to close their accounts as well since shared profiles does not get automatically deleted and just inherited by the closest user.
You find the close account option under Account Settings in the menu under your name in the upper right corner.
The easiest and probably quickest way to get rid of your ex-wife is to log on and delete the profile y clicking the [x] in the node of her in tree view. If you don't remember your old login you can recover it or ask one of the other users to just delete the profile for you.
That would not destroy the tree for the other users and they can still maintain and build onto it.