What is the correct process for changing employers regarding visas and work permits in Thailand?

I am switching companies, need some help understanding the correct process between my visas and work permits.

My question is this the correct process, and also is it possible to get my new work permit with my current non b?

Here are the stats...

I currently have a 1 year non b from Penang, it is good until March 2019. On the visa is the name of the company that sponsored the visa, it is hand-written in Thai.

I HAD a work permit that was due to expire this week, last week at the labor office we canceled through some understanding from the labor dept as that was the correct thing to do.

In order to get a new work permit and eventually get to a 1 year extension stamp, what is the correct process?

My understanding is:

1. Get the invitation letter from the labor department

2. Exit Thailand, get the non b at an embassy

3. Come back into Thailand

4. Get the work permit for the new company

5. Go to Chaeng Wattana for the 30 day stamp

6. 1 month later get the 1 year extension

Any and all help much appreciated!