How do I get my ex out of my property?
I am the sole owner and I let her live there with our son. He now lives with me. So I texted her giving her the option to purchase or I would start eviction. She replied if I contacted her again she would call the cops for harrasment.
As the sole and legal owner you have every right to request that your ex-wife remove herself from the premises. If she has paid rent (or a form of rent such as the utilities) she is a tenant; if she has been a long term guest than she is what may states deem to be a "licensee". In either event, she must be provided written notice to vacate the premises. If she fails to remove herself by the date specified then you will have to formally evict her. In other words you will have to file for an "unlawful detainer" in court. Once a judge finds in your favor they will issue you a writ of possession (or your state's equivalent). If your ex fails to leave at that point, then you can have a sheriff forcibly do it.
In the interim do not be tempted to use any self-help measures (e.g. changing the locks, removing her belongings, etc). You could be sued for unlawful eviction if you do.
At this point, your best bet is to consult with an attorney who specializes in landlord-tenant matters. They can advise you as to state specific procedures.