Can I make prediabetes go away?

Unlikely. Prediabetes implies the eventual development of diabetes, which is usually genetically predetermined. So at best, aggressive management of prediabetes can delay the onset of diabetes. That being said, blood sugar measurements can be adequately controlled at times with diet and exercise alone, without medications.
Yes. You must aggressively change your lifestyle. Mobile Health games can help. Physicians recommend water, increased veggie intake and walking 10k steps a day. Changing your behavior is HARD! Here is a health game that will help! Commit to tracking your nutrition and weighing in weekly. Losing just 10 pounds can reverse diabetic state. https://itunes.apple.com/us/app/personal-medicine+/id846379884?m.
Yes. Prediabetes put you at high risk of developing diabetes. To prevent that from happening you need to maintain (or attain) a normal body habitus. That means a normal weight. You should have guidance about diet from you doctor or a dietician. Typically that means limiting the sugar and starch in your diet. Moderate exercise is essentially.