You don't. You present the facts, show the evidence, they say "oh", and then the next time you see them it's either forgotten, or dismissed as irrelevant. They change the angle slightly to avoid the knowledge that doesn’t fit with their narrative.
Arguing with facts just gives you a headache. The phrase I use a lot, is we have to agree to disagree and change the subject to one that hasn't been hijacked by conspiracy theorists and the far right.