Unfortunately, (or fortunately, depending on which side of the fence you sit) it is not possible for parents to “divorce” themselves from their children nor is it possible for children to “divorce” themselves from their parents.
If children are under 18, obviously, parents can put children up for adoption but after 18, they remain children and parents for ever.
Unfortunately for your son, is now stuck with you. He can demand what he likes, and even if you wanted to do something about it, there is nothing that you can do.
All he can do and all you can do is sever all contact.
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