You have to get them to realize they're being lied to. Doesn't really matter about what. They need to know that the sources they trust and believe are legitimate will and do boldface lie to them. That seems to be how people get redpilled. When they know for a fact the media is lying. Then they start to question what else they're being lied to about and will be more receptive of new information. Until that happens the cognitive dissonance is to strong. You can literally walk them in a circle logically to where they're agreeing with you and the moment they realize it their brain will short circuit and they'll purge everything an repeat their original point.