The dreaded Bingo arms, you know where the stereotypical older female raises and shakes her arms to call bingo and the bottom half flaps around. Unsightly I know, but it happens to various extents and people want to get rid of it fast. The problem is you can not site reduce. This is the idea that you can lose fat from a specific area by targeting it, the same holds true for the mid section. If you have not figured it out by now, the body is unfair. Your individual body chemistry can place fat unevenly but it takes it away evenly. This is genetic and environmentally determined. This is how we get pear shaped people and apple shaped people. Taking off the weight is done equally for the most part. So say you loss 1% of fat, it be taken from every fat store on your body divided relatively evenly.
This means to improve the look of your arms you need a total body program of diet and exercise. Most diet requires a caloric deficit of 500 calories a day in order to total 3,500 calories a week which equals a pound of fat. This should be coupled with a whole body strength program and cardio training. A three day strength training program in a circuit format will build muscle and burn fat. Adding muscle will help burn fat all day and tone up muscles, adding extra arm exercises may add a slight benefit. Two to three days of cardio will burn fat and increase your ability to work hard.
Unfortunately there is no easy way to improve a specific area of the body; it has to be a global effort. A positive lifestyle change is great for your well being and looking great a nice benefit.