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If she is acceptable to the divorce, you are going to have to get her to acknowledge service of the divorce complaint by signing for same in front of a notary public. Here is a great flowchart for the process http://www.courts.state.co.us/Forms/PDF/JDF%201095%20Flowchart%20Divorce%20with%20no%20children.pdf
Instructions are here, http://www.courts.state.co.us/Forms/PDF/JDF%201099%20Instructions%20for%20Dissolution%20or%20Legal%20Separation%20with%20out%20Children.pdf
General steps in the process are here, http://www.courts.state.co.us/Forms/PDF/JDF%201097%20Steps%20to%20Complete%20a%20Divorce%20with%20no%20Children.pdf
The fact that she does not live in the US should not impact you greatly, provided she wants the divorce as well. The problem becomes when she does not want the divorce and wants to frustrate the process.