Won't necessarily be cheap, but the easiest way is to get a body side connector to the seat which per the wiring diagram from koolkat68, you should just be able to apply 12 volts from a battery.
Not the easiest way, but it will certainly work. That and as mentioned by others, this will give you an easy way to adjust the seat over time or for other drivers in your game. You know if you ever allowed guests to play
Hard is that connector is likely part of a much bigger wiring harness so $$$. Maybe junk yard or on line???