When you order "scale" couplers with your American Models passenger cars, these are the ones that they come with. They are dummy couplers. They work well, as I have seen local modelers run full consists of these passenger cars on a layout. You have to manually lower the next car down onto the previous car's coupler, but it works. The reason why American Models makes these truck-mounted couplers is so that these long cars can still run on tight-radius curves on layouts. The downside of truck-mounted couplers is when you try to back them into a spur or siding, you will likely wind up derailing one or more cars. Removing these is nearly trivial. Simply remove the screw holding the coupler bar to the truck, then slide the bar out of the truck. That's it! Note the hole in the underside of the body on the right...
On this particular car, one side had the hole pre-drilled, but the other side just had it marked but not drilled. When I lined up a couple of "scale" couplers I had on hand, I noticed that none of their center holes lined up with the pre-drilled hole in the car. Since my coupler standard is the Walthers ProtoMAX HO-scale coupler, I used that one. To be able to get its center hole to line up with the pre-drilled hole, I had to file off the lip on the top side of the coupler's gearbox. On the other side of the car, I was able to mark off and drill the hole myself and was able to preserve the lip on the coupler. I don't use the Kadee magnetic uncoupling system, so I clipped off the wire. The coupler's gearbox has two more mounting holes, but I found that it is on the body tight enough that, for now, I am not going to install the extra screws.