I take it you have a thai bank account so you have two options put in the
*****
0thb or give a agent about
*****
to do the paperwork
But firstly you need to leave the country and get the 45 day holiday visa and then you can go to immigration office to apply for an 1 year extension on retirement visa they will provide the information for you to do the paperwork the cost for your application is 2000thb then 1900thb every year after that