Can you tell me how to reduce the size of my arms and back. mainly triceps, deltoid, trapeze, and (side) back fat?

Diet & Exercise: This may sound like common sense, but the best way to lose body fat including the areas you are targeting is by a combination of diet and exercise. The recommendations are for at least 30 minutes of moderate intensity exercise most days per week. A combination of cardio and strength exercises will keep you fit. Your diet should be balanced and based on your desired weight.