To file for an annulment, the first step is to make sure that you meet the requirements, meaning the marriage has to have been fraudulent or forced or between blood relatives who didn’t know of the relation. You have to meet residency requirements for your state also. Forms to file for annulment can be picked up in the family court. Go there or to the website for the court to see if the forms are available. You will then have to go to a hearing.