to dissuade him or her from it
J'ai essayé de l'en dissuader.
I tried to dissuade him.
M. Zuloaga essayait de l'en dissuader.
Mr. Zuloaga was trying to dissuade him from it.
— Parle avec elle (2002)
Nous devons l'en dissuader.
We need to talk him out of it.
— La Chute (2004)
Il tentait de l'en dissuader.
He was trying to talk him out of it.