You can convert from tourist to 90 days "O" retirement with a one year extension at the end of the 90 days. Not all immigration will do it just check with the one closer to you. No medical or police papers needed. All done inside Thailand.
Sorry Tod i forgot to ad that they do NOT accept first Non O retirement application because she ask if i had an Non O before witch is no in my case. In short she will have take my application if i had an Non O before.