Hey.
I don’t think you need a legal advice for this but a personal advice.
Best is to have a word when he is in right mindset.
Or learn how to bring him into right mindset.
Or find someone from relatives/his friends who can help you in convincing him
Or just become a politician. That is, keep him convinced that you’ll do but don’t do.
And honestly, these are just normal ways of dealing with people.
Legal advice should be the last resort, left only for extremest of the extreme situations, when you’ve failed in every diplomatic way.