My calves are very muscular and look too big on my small body, how do I make them smaller

Perhaps something that you will find on the following search might be helpful to you?

Toning Calves - Google Search (http://www.google.com/search?hl=en&safe=off&q=Toning+Calves)

Do you run? What kind of workout? Curious if this is just natural or whether you work out and what the program is?

Do you do any upper leg work, especially hamstring? Working your quads and your hamstring can balance your leg with more definition up top.

I'm not 100% sure on this but I think that is hereditary to develop large muscle mass like that.