Hackers Help: Arild Sofa – replacing the legs?

A friend recently purchased an Arild sofa and chair second hand but hates the metal legs.  I flipped the chair up and can see they are attached with an alum key so I can remove them easily enough but can I replace them? I’m pretty handy at DIY but I’m a little worried that the metal bar that runs around the bottom of the chair/sofa might be structurally important somehow in which case removing it and replacing it with wooden feet could be a problem.  Has anybody else tried it?  Any ideas as to what might work?