The 16 way seats are a direct swap in for the 6 way.
Only the driver's 16 way has all the extra features (adjustable thigh support, inflatable lumbar support) while the passenger side you only get power recline and there is an extra plug for the recline motor. The passenger side lacks the other power features of the 16 way driver seat.
The extra harness for the 16 way seat is already present under the drivers seat so the seat can be hooked up and bolted in. The three extra function switches for the drivers seat are located on a pod mounted to the side of the seat bottom, so there is nothing to add to the switch panel located on the door.
A few cars have been converted to have the full blown drivers seat on the passenger side, but you must start with two of the 16 way drivers seats and remount the controls from left to right on the passenger seat.
Thanks to members of the Reatta forums for this information.
