Armstrong/Lennox Magic Pak Help

[BlaineD]

 I am working on an Armstong/Lennox Magic Pak. Needs a new combustion blower. I removed the 2 screws and it is supposed to slide out but I believe there is a rust issue. Does anyone know if the outside louvers can be removed to get to the combustion exhaust. I think if I can get that exhaust pipe off then I can break the combustion blower loose. Any thoughts?