The very long aluminum angle pieces that run the length of the fuse are provided in the wing kit for shipping purposes. Guard them with your life and do not cut them. They are 14ft long and very awkward.
Once your ready, the bending takes place. There are compound curves in these so great care must be taken in bending them. First they get stuck in a vise, the 2 of them clamped together. Mine are partly in the garage, then running through the door into the living room downstairs.
Then you put some weight into them to get them to bend together as a pair. The plans cover this very well.