First, make sure to let Trump supporters know how stupid they are. Pull up a study that says educated people, like yourself, are less likely to support Trump to prove your point. Then, flaunt how much smarter you are than they are. Let them know they're deplorables, and that if they lost their jobs or are going to lose their healthcare, they deserve it--especially the white working class. Because that's what they asked for when they voted Trump. They voted against their self-interest. Those dumb hicks and rednecks just don't know what's good for them.
Let them know they're racists, bigots, sexists, xenophobes, and have their heads in their asses stuck in the Jim Crow era. They're sexists especially since they didn't want Hillary Clinton, the most qualified person to ever run for President, to break the glass ceiling. Ignore the fact that many of them voted Obama. Neglect the fact that the DNC was heavily biased in the primaries against Bernie Sanders, since they fight for the right ideas, they can't possibly be corrupt. Let them know they're privileged because they didn't have any consideration for your black, latinx, female, LGBTQ, and Muslim friends. It's alright that you always forget about Native Americans when you fight for minorities, and only remembered they were there once it became a trend to tweet #NoDAPL.
Let them know, verbatim, what John Oliver said last night, and then pat yourself in the back for being so funny and original. Ridicule them--that's always the best tactic. Make sure to destroy them for reading fake news like Breitbart and Fox News, and then brag about how you read credible sources like The Huffington Post. Make sure to show them articles from The Borowitz Report, and then say "look at how ridiculous your President is."
Let them know they're on the wrong side of history. If they say something remotely racist, make sure to announce it to the world so no one can forget how much they deserve to be shunned. Attack anyone else that dares defend them as racist as well, and smirk at what a phenomenal debater you are. Never accept the despicable racist's ignorance for an answer, and never, ever forget so you can bring justice to Neo-Nazis like said Trump supporter. Until tomorrow. Oh, and you can't possibly ever be racist either. Liberals are immune from that.
Let them know that Donald Trump is exactly like Hitler. Then shame them. Use your favorite words: Racist. Nazi. Misogynist. Make them feel so ashamed that they can't possibly support Trump anymore. Oh, and since Trump didn't win the popular vote, their president is illegitimate. He only won because of Putin and Russia. Make sure to shake your head whenever they mention manufacturing jobs. They're not important and being lost to automation, so why are we talking about them so much? Then end the discussion right there, and don't worry about any relief for those workers. Make sure to let them know that outsourcing isn't a real issue. Free trade? Who cares?
Above all, make sure to forget that Trump supporters are human beings, with insecurities and problems that parallel your own. Let them know that it doesn't matter if they love their spouses, children, and neighbors. It doesn't matter if one of them helped you jump start your car the other day while everyone else just drove by. It doesn't even matter if they regularly volunteer at the soup kitchen. Because they voted Trump, they are terrible people that deserve to be damned.
Follow all these steps, and before you know it, Trump supporters have changed their minds. Then pat yourself on the back again one more time, because above all, you did the right thing.