How to become a Vegetarian?

I am not a meat addict. I am not all about the protein or anything it's just that I saw a video a couple of minutes ago on how they kill animals and make food such as chicken and pork (which I don't eat anyways because I don't like it.) I mean I eat hamburgers and hotdogs but after watching that video I wouldn't touch them with a ten foot pole. It almost made me cry on how those animals have to go through a slow and painful death just so we can eat! It's disgusting! Like I said is their things that vegetarians answering do to stay away from hamburgers and hot dogs if they used to eat them? Do you have any tips? I have seen a lot of videos and some of them I have seen the point but this one kind of phased me. Any tips? Thanks!!