It is possible to lose 10 kilos (about 20 pounds) of weight in a month, but it does take resolve and firm commitment. You need to exercise regularly. More importantly, you must change your diet -- the fewer calories your body gets, the more fat (and muscle) it has to burn to function, and the more weight you will lose.
Also important is the kind of calories you consume. You need to avoid simple carbohydrates and concentrate on low-fat, complex sources of carbs, protein and fat.
Eliminate all simple (white) carbohydrates, like bread, rice and pasta from your diet. The only exception to this rule is an hour and a half before or after a resistance (weight training) exercise session.
Increase the amount of vegetables you eat. Vegetables have carbohydrates, but they are complex carbohydrates that are easier for your body to process without storing as fat. However, they are also much less dense in calories, so you will have to eat a lot to compensate for the lack of simple carbohydrates.
Perform regular cardiovascular exercise. The best exercise for weight loss is interval training -- one minute of easy cardio followed by a minute of hard cardio, repeated for about 20 minutes. This shocks your system into burning more fat after you leave the gym.
Replace soda, beer and other high-calorie drinks with water.
Reduce your total calorie consumption. This is the key point, and to effectively lose 10 kilos in a month you must reduce your calories by quite a bit. The actual amount, of course, will differ from one person to another, but you should eat substantially less than you usually do.