What is a one-sentence summary of the following article?
If you're sure you want to call off the engagement, do it as soon as possible. Even though it might be scary, it will only cause more harm to your partner if you put it off. You should never break this kind of news to someone over a text message or email, no matter how nervous you are about the other person's reaction. As hard as it may be, the right thing to do is to have an honest face-to-face conversation with your partner. A phone call is better than a text or email, but a face-to-face conversation is still preferable. It's important to be upfront with your fiancé(e) about why you don't want to go through with the marriage and what you want the future of the relationship to look like. If you never want to see your partner again, don't say that you might be able to work things out down the road.  There's no reason to bring up every disagreement the two of you have ever had. While you do want to give a reason for the breakup, don't go overboard with a laundry list of complaints. Make sure to give your partner the opportunity to ask questions, and always answer them sincerely. When it comes time to tell your fiancé(e) that you don't want to get married, it's important to be as tactful as possible. You want to make the breakup as easy for both of you as it can be.  Never yell or call your partner names when breaking up. Even if you are calling the relationship off for good, there's no reason you can't acknowledge that you will miss your partner. Depending on the situation, you can even explain how much your relationship meant to you.

Summary:
Don't drag your feet. Talk in person. Be straightforward. Be respectful.