[SapphireRain]

You tend to lose fat from the areas you work out so if you do a lot of exercises that are targeted towards your arms, that should help reduce the fat there and tone your arms at the same time. Make sure you are doing a broad enough range of exercises to work out all the areas/muscle groups of your arm and shoulders and not just repeating one exercise over and over.

Cardio should also help you lose weight... but that's more of a general full body weight loss rather than weight loss from your arms. Good luck!