To begin, one of the two parties in the marriage will need to file a Petition for the Dissolution of Marriage. Whichever spouse files the form is considered the petitioner, and the other the respondent. Once the form has been filed, the petitioner must provide a copy to the respondent, a process called serving.
At this point, you may start down one of two paths. Should the respondent agree to the divorce, they accept the service of the papers. From there, they will need to fill out a form called an Answer and Waiver of Service.
However, if the respondent does not accept the service of the papers, your divorce process will become more complicated. You can work with the county sheriff to serve the papers. Similarly, you can work with a constructive service to serve the respondent if you are not sure of their location.