I have a non O imm visa and am switching to a retirement visa. Currently my farang  wife of same country is gets her visa (also none imm O) because I have one. Now that I am switching to a retirement visa. Can she once again get her visa attched to me? How does that work?

There is no switching of visas. You simply apply for a one year extension of stay at immigration.

After you get your extension of stay she can apply for an extension as your dependent.

She will need your marriage certificate that has been legalized by your embassy or the government entity that issued it (and translated to Thai if not in English). After that she will only need copies of your passport photo page and extension of stay stamp.

 

Once you've been issued an extension of stay based on retirement your wife qualifies to apply for an extension as your spouse. 

 

If you are both within the last 30 days of your respective 90 day permits to stay you should be able to apply for your extensions on the same day.

 

Regardless of when your wife applies, her extension will be for the remainder of yours.