What are the requirements and process for applying for a marriage extension visa in Thailand while on an OA multi-entry visa with existing stamps for extended stay?

Here on an OA multi entry visa, which expires in October, but have stamps extending my stay in Thailand due to trips outside the country. Will be making other trips prior to expiry in October. So I assume I have until the expiry dates of the stamps to do the Marriage extension. Have had about 500,000 in my bank account now for a few months. Has anyone done a helpful in this group on applying for the marriage extension? That way I dont have to bother people with repeat questions. What I have told you about my scenario so far raise any red flags? Married in Canada in 2014.