Eating less and exercise more is the BEST way to lose weight and stay healthy. To lose that much weight in such a short period of time, you need to do some plannings. One thing to plan on is the amount of calories you are going to have each day. It takes some trials and errors. You will need to find out what your body's tolerance is. In other words, you can't starve yourself over a long period of time.
As to exercising, start out with an easy routine. Maybe walk for 30-45 mins a day. Gradually increase the intensity. Make sure to vary your routine so that your body doesn't adapt to one routine. This way, your body burns more calories.
Don't forget weight training. Building muscles help burn more calories. So, integrate weight trainings into your routine.
Stay happy and get plenty of sleep. Sleep deprivation can sabotage your weight loss effort.
Cheers!
Terry