You will need a flat blade screwdriver.
1. Pull the front edge of the rear seat cushion and release the cushion retaining tabs.
2. Lift the rear edge of the rear seat cushion to release the seat belt buckles from the holes in the cushion and remove the seat cushion from the passenger compartment.
3. Fold the left side of the rear seat back (see «Backseat»).
4. Press the spring-loaded washer of the left fastening of the left side of the backrest with a screwdriver...
5.... and remove the left mount from the holder on the body.
6. Remove the left side of the backrest from the bracket axis and remove it from the car interior.
7. Similarly remove the right part of a back of a back seat.
8. Install the rear seat in the reverse order of removal.