how do you go about filing a restraning order on someone and what do you need to do it

The answer depends on weather you have a family law case or not. If part of a divorce, it is filed in the court weer the divorce is pending. If not, there are several possibilities. If part of a business relationship problem it is filed in a county or district court depending on the nature of the problem. I would suggest a consultation with a lawyer to see where the filing should be made. The answer depends on many things that are not in your question.