From where I am sitting that looks like a wood screw holding on the motor bracket...yikes!! I hope a dealer didn't do that.
Remove the bulb from the light and then remove the shade. The part holding the switch, sitting in the hanging metal housing, should slide out and if you're lucky there are screw terminals for the wiring, otherwise use the existing wire or break out the soldering iron. That housing holding the switch just pushes back into the housing still on the light bracket. But all that comes apart as well, you can see the small set screw and the ring on the motor side of the light bracket unscrews.
the motor wiring looks fine up to the first plug visible in the picture.