Go to local court house

It is simple. Go buy a divorce guideline package from local court house. It will give you all the instructions. It only takes 3-4 month to get divorce paper and costs about 300-400 bucks. Of course the court starts to process your application after you two seperate for 1 year (you need to fill out seperation date in the forms).

Call your local court house for detailed information.
No need lawyer and no need go to chinese consulate.