Oh, you wanna go back to the Dark Ages? Okay, the first things you have to do are stop using your computer, your car, quit your job unless you're something timeless an ancient like a baker or a tailor or something like that. Then you have to give up your rights, liberties, and home to your Feudal Lord, who controls everything that you do and makes you grow food for him and his family in exchange for your "right" to live on his land. Stop reading, writing, and thinking because you wouldn't have been able to learn ANY of that. If you ever had flu, chicken pox, broke a bone, had a major injury of any kind--just kill yourself now, because if this WAS the Dark Ages you'd never have survived it.
Oh, and you would have very little food and would spend whole winters eating salted meat that really doesn't stay "good" for very long so you'll probably get pretty sick from eating rancid bacon. About half of your children would be dead because infant mortality was extremely hight. Your wife, too, would probably also be dead because childbirth was dangerous and often led to infection. You own only one set of clothes and probably no shoes. You live in a thatch cottage that's made of mud and animal poo; if you're not careful, the very fire that keeps you from freezing to death will light your whole house on fire and you will lose everything you own.
DOESN'T THAT SOUND LIKE FUN??? YAAAY, MIDDLE AGES!!!