Only one thing: cut carbs.
If you intake less than 30 grams of carbohydrates per day, your body will need to burn fat in order to maintain a proper blood glucose level. Over time, you'll lose weight from fat.
If you're lazy, this should be easy to implement.
You can speed up the process by lifting weights, easily done with compound lifts that only require 20 minute workouts two or three times a week. If you want to work out or do strenuous activity, eat more carbs on workout days, especially post workout.
Once you're getting close to a healthy weight, your insulin sensitivity should be higher, and you can start working in more healthy carbs like brown rice, oatmeal, yams. Fiber, cinnamon, and vinegar also help slow down the glycemic response from carbs.