There are two attachment points on the parcel shelf itself and two on the trunk hatch. When the parcel shelf is attached, cords run between attachment points on the parcel shelf and the trunk hatch.
The cords have loops at each end that you hook onto the trunk hatch attachment points.
Detach each cord from the trunk hatch attachment points.
The shelf is loose but still lies flat in the same position.
Lift the shelf from the hinges at the back, near the rear seats.
Carefully move the parcel shelf towards you until it is completely removed from the trunk.
Store the removed parcel shelf somewhere it won't get damaged or be in the way for other people.
Note
Keep in mind that large objects stored in the trunk can reduce your driving visibility.