Losing such a large amount of weight in so short a period is possible, but not safe. Exercise and diet are the main things here; there is no way around it. Start by replacing the junk food in your kitchen with healthy vegetables and fruits. Drink a lot of water and exercise; start with walking, jogging, running and ten you can go to rope jumping. Consult a weight loss professional or nutritionist for professional advice.
Its possible but not safe and healthy. I was going to try to do the same as you but the only way to do it was without eating. First of all try to cut 500 calories from the food u usually eat. Example if use consume 1900 calories a day (note you should know your basal metabolic rate) and instead eat 1400, in one week youll lose one pound. Of course healthy food. Youll need exercise also. Be careful with over-working. You can follow my routine: I use the workout trainer app for workout routines. I totally recommend it. I choose a different workout every day. Try exercising 4-6 days a week. If not 3-5 days a week. Then I do some weight lifting and push-ups for 10 minutes. Later other 10 minutes of crunches. After that Im really tired but I rest and then I run for like 10 minutes and do boxing for other 10 minutes. Try to do 30 minutes or more of exercise Note: dont count the pounds lose cause youll be gaining muscle and it weights more but youll fisically see changes and after some weeks or months youll be able to see changes on the scale. Use this site for lots of information: healthstatus.com. You can follow my routine or make some changes to make it easier but focus on cardio workouts anf toning muscle. If you follow my workout youll feel like you can do everything. Trust me the next day youll feel like you can run the world. Hope I helped. Oh consult a proffesional also to avoid some damage, injuries or over-working.