I have fats on my stomach only. Other side I'm thin. I want to lose stomach fat and increase muscle. What should I eat or do to speed up the process.

Exercise, eat less. To gain more muscle do weight resistant training. The good news is that you will also lose weight! Eat a low carbohydrate diet. Move, move, move. In males fat around the abdomen is called "apple shape" as oppose to woman "pear shape" (fat accumulates in hip and buttock area). Hormones are causative. If you are doing the above and not improving you may need to have your hormones checked.