To lose fat from your face you need to do the followings:
1). Regular body exercise, including walking, jogging, running etc. Do any of these regularly for at least 3 hours in 3days of the week. Exercise will convert your body fat into muscle.
2). Eat proper balanced diet - Eat plenty of fruits and vegetables. Drink plenty of water. Reduce salt intake in diets.
3). Do facial exercise - perform lips, cheeks, jaw and chin exercises. This will help to reduce your face fat
***Just correcting some points from above answer:
It is true that exercises will help you lose the fat, but it does not turn fat into muscle. And you cannot spot train to lose fat. Fat is lost from all over the body by percentage. Facial exercise might help you to have better expression, fights wrinkles and whatnots, but has virtually no effect on fat loss. Just do the exercise mentioned in the above answer, and just dance around for an hour in your room on your off-days :P