Going back in time to the moment before the dude who invented fascism thought of it and distract them so they never actually have that thought. Bam! No more fascism and in a 100% pacifist run.
Soo, showing up in leftist reporter Mussoliniโs home to debate his current thoughts about a new type of revolution, bringing a gun just in case. I donโt know if thereโs any amount of distraction you could subject Benito to in order to prevent him from thinking up fascism. Youโd either have to make him realize itโs stupid or kill him.
Addendum: donโt forget to practice with your handgun beforehand, and bring something to smash a windshield beforehand. This is why there were 8 failed assassination attempts on him.