Changing From Non B To Non O

[JohnOFphon]

Ok, I poured over the Immigration site and couldn't find a clear answer. Yeah, I know, that shocks you...

My Non B (teacher) 90 day extended to one year, visa will expire soon. I have a Thai wife of 3 years now and want to change back to a Non O. I changed from my original Non O to a Non B because I believed some fool at the school where I work. He told me I had to have a Non B to work here. File that under..lessons learned.

Now, my question. Do I have to leave the country and reapply for a Non O or can I change my Non B while in country?

What documents will I need for either. I read what they require on the immigration site, but maybe someone has a recent experience that would be helpful.

Thanks in advance

John