To fold down a section:
1. Locate the release levers: These are usually located on the inside of the rear seat back, near the top of the seatback itself. They might be small levers or straps. Check both sides of the seatback, as they aren't always in the same exact spot.
2. Pull the release lever(s): Pull the lever(s) for the section(s) you wish to fold down. You may hear a click or a slight resistance as the latch releases.
3. Fold the seatback down: Gently push the section of the seat back down to lay flat. It should fold forward into the space of the trunk.
If you can't find levers on the inside of the rear seatback, consult your owner's manual. The location can vary slightly depending on trim level and specific options on your vehicle.