If the switches and seats are still in the car, I don't see why you can't hook up a battery temporarily (just to move the seats).

Easiest way is to just hook up an old battery (or jumper pack) to the positive and negative battery cables in the car. Then operate the seats enough to get them out.

If that doesn't work, look at the wiring diagrams and see which wire supplies +12V to the power seat switch and cut/connect that wire (plus a ground) to a battery.

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