What if: a war between muggles and wizards?

Let's say a deity or something drops you in the body of Voldemort with his memories and total control of his magic, in a reality he won, just after taking over the world. The muggles notice and declare war against wizardkind. How would you wage war against 6 billions or so muggles and their weapons? You keep all your knowledge of the real world.
Wizardkind will follow your orders without resistance because they fear you and believe only you are strong enough to lead them to war