I want to lose 20 pounds in about two months what is the best way to do so?

Ok so its summer time and im overweight and im tired of looking in the mirror and seeing something i dont like i want to be able to look in the mirror and love what i see im embarrassed to go out in public and i want that to change so i would really like to know what is the best way to do so. Can anyone help me please. I would like to do this is two months because thats when school starts back up