What are the steps to take when changing jobs regarding the Non-B extension and Work Permit without leaving Thailand?

I'm going to shut down this post.

1. Teaching license waivers are *NOT* Thai visa related at all. There are countless teaching in Thailand groups that can answer the question.

2. Work permits are only tangentially related to Thai visas. You *CAN NOT* work in Thailand without a work permit. If anyone wants you to work without a work permit, it is illegal.

3. Extensions of Stays *ARE* within the scope of the group. Changing jobs in different provinces inside Thailand without leaving Thailand is possible, but logistically difficult and requires both the current and future employers to work closely together, and the immigration offices willing to work together as well. MAKE SURE both schools are willing to work together before trying to get a new extension of stay. See Tod Daniel's comment above.

You will have to apply for a new teacher's license as you are moving to a different school. This might cause an headache.

you coordinate with the current employer AND the new employer along with the immigration office and the ministry of labour (the work permit people) so you can cancel the extension you're on now based on employment from your current employer and immediately apply for a new extension based on employment from the new employer.

Different cities doesn't matter as long as they use the same immigration office. The minute you switch immigration offices then it doubles the amount of coordination you have to do because you're canceling an extension at one location and applying for a new extension at another one.