Exceptionally difficult for 2 strong and flexible adults to put together!  It took massive strength from one to hold two pieces in an "aligned" way while the other got the screws/bolts all the way through both and into the chair.  we ended up turning the main chair piece upside down OVER and into the packing box to support t well enough while we practically body-slammed the long nuts" into the holes.  There was fabric over the holes (not sufficiently cut away) that hindered and entering bolt from grabbing on to the receiving orifice. So, we trimmed that before starting on the second chair which helped, but the gymnastics were still required to get to that point! 
In the end, the chairs ans ottoman are very attractive.