How do you turn villagers into zombies?

To turn villagers into Zombies in minecraft, you must first ensure that a zombie attacks a villager. When a zombie comes into contact with a villager, it has a chance to infect the villager, turning it into a zombie villager after a brief period. To increase the likelihood of this transformation, you can use a zombie spawn egg or create a dark area where zombies can spawn and find the villagers. Once the transformation occurs, the zombie villager can be cured using a splash potion of weakness and a golden Apple.