Take pillows, cushions and anything else off the sectional couch.
Have your helper assist you in picking up one piece of the sectional couch. It should freely pull away from the assembly.
Repeat for the other pieces, one by one, until the sectional couch has been broken down into separate parts.
Locate the locking pins on the different parts of each sectional piece. Generally, the pins can be found on the ends and in the center of each piece. Grasp them with pliers or vice grips, then turn counterclockwise until the pins are unfastened from the couch. Put the pins into a sandwich bag for safekeeping.