2 wires connect each motor to the controller, fit them backwards and the mover just goes the opposite direction to the button. Swap them around and sorted.
2 wires from the battery to the control box. One wire goes through the cutoff switch.
Dont get the positive and negative on this and your all good to go. The wiring is really is that simple.
Unbolting it will involve crawling under the van and lifting the motors and brackets into place and removing it depends on how long it has been fitted, any rusty bolts etc?
Someone thats done a few before will have it off in under 20 minutes and refitted in an hour or so.