Your back seat has front hinges bolted to the floor, and a system of several cables which first release the back rest, this makes the back rest fold so you have an additional flat cargo space, however at a higher level from you cargo area on the back.
Further pulling, releases the rear latches which enables you to fold the complete assembly forward until its standing up behind the driver and passenger backrests.
The cables are concealed beneath the rear upholstery of the back rest, and are connected to a short strap which is supposed to reach out of the back rest in the lower section.
I might be slightly wrong about the actual sequence of operation, but this is roughly what's going on there.
You need to remember to detach the head rests from the back rest before folding.
a nice feature, is a place to reattach them on the seat afyer you fold it, so you dont loose them.
Good luck
Omri