Removing and Replacing Jackknife sofa in Excella 1991

[groundhogy]

Hello,
We need to remove the jacknife sofa from our airstream and replace it with a new one(another jackknife for space concerns). How do we get it out, and the arms, and does anyone know a good company for replacements?

It's a 1991 Excella

[SeeMore]

The folding couch back has bolts at the left and right hinged junction with the lower frame. Remove those bolts and the upper back will separate. The lower section is screwed to the floor. In the attached file you can see the screw heads on the black railing that contacts the floor surface.

[groundhogy]

How do you remove the arms?