Typically, Rail King cars have 4 screws holding the car together. Two screws at the extreme ends which are smaller in diameter hold the interior insert in place. Just behind each of the insert screws are two larger diameter screws holding the roof of the car in place.
There is no need to take the insert out if there are access holes in floor of the insert to get at the truck mounting screws.
There are two wire leads to each truck, and these leads terminate on the insert. Disconnect the leads from the truck. One is a slip-on connection to the pickup roller, and the other lead connects to an axle wiper pickup with a small screw.
Take out the roof retention screws (2 Phillips head). Grab the car buy its ends and twist the body until the roof pops loose.
