Installing and removing the rear bench seat
WARNING Risk of accident and injury as a result of rear bench seat not being engaged
If the rear bench seat is not engaged, it may be flung around during travel.
Always make sure that the rear bench seat is engaged as described.
Removing the rear bench seat
In vehicles with a seat rail system, carry out the release, removal and subsequent reinstallation of the rear bench seats at the marked basic setting only More.
Make sure that all carriages for fore-and-aft direction are engaged on both sides.
It should not be possible to move the rear bench seat.
Fold the rear bench seat forwards More.
Pull the release handle 
upwards.
upwards. Hold the rear bench seat by the grab handles 
and lift it out of the seat anchorages 
.
and lift it out of the seat anchorages . If the second rear seat row is to be removed or tilted, the seat or bench seat in the first rear seat row must first be tilted forward to avoid damage to the seats.
Installing the rear bench seat
Hold the rear bench seat by the grab handles and guide it into the front seat anchorages at an angle from above.
and guide it into the front seat anchorages at an angle from above. Tilt the rear bench seat back and allow it to engage.
The release handles 
fold down towards the vehicle floor.
Fold the rear bench seat back into the seat position.
The rear seat anchorages of the rear bench seat are correctly engaged when the seat anchorages engage audibly and the indicator tabs on the seat anchorages are no longer visible and have fully retracted into the seat anchorages.
Slide the rear bench seat into the basic setting More.