Three seat sofa bed IKEA FRIHETEN (FREEDOM). How To Assemble friheten ikea?

Ikea friheten sofa is practical, converts easily to a full size bed. It is slightly bigger than a standard double bed. Comfy as a couch and as a bed, with plenty of storage. But do not wash. Only vacuum clean and wipe clean with a damp cloth. How To Assemble IKEA FRIHETEN?
PS. Ikea friheten sofa is not broken even 3 years later...