Can I change my Non O visa extension from retirement to marriage?

yep, you either wait until this current extension is going to expire and then apply for a new extension based on marriage instead of retirement OR if you're wanting to do it sooner you go cancel the current extension you're and immediately apply for a new yearly extension based on marriage to a thai.

I suggest you and your thai wife GO to the immigration office and get the hand out listing the required documents, copies, photos, map, etc to get the yearly extension based on marriage.

When you apply for a yearly marriage extension you will get a 30 day under consideration stamp (and usually during that time some immigration officers will come do an in home visit) then you go back to the immigration office when that under consideration stamp expires and they ink in the year extension