OK. If you have been married before get a court document from the court in your country where the divorce was done. This will need translating when you are here.
A friend of mine did it in Nakhon Sawan but it's better to get a tourist visa as it gives you more time to prepare the documents etc. It's was a real push to do it.
Phone 1178 and they will confirm what you need. If the immigration office start stating differently out them on the phone to the immigration officer. Worked for me