^ ^ ^ The DEF side just needs an Allen key to widen or narrow the seats.

The ABC side has the Allen key to do the widening (and scrunching of the B seat) - but there is also a mechanism under the middle set of headrest ears that also has to be twiddled - this makes sure that the right bits of the seats recline in either config.

If you lift up one of the headrest ears you will see some arrows ET<>CE or something like that.....