How do I cange or clean the filter in a Miller CMF series Furnace, I can't even find a filter

http://www.nordyne.com/Literature/7086930.pdf


I believe the filter is on the door of this furnace. Does the door on the front have louvers? If it does the filter goes there. There is also supposed to be a metal wire contaption that holds the filter in place.

Part number 669072 filter

Part number 669647 retainer