I do not have one in front of me, but if the mounting "plate" that the coupler rides on is sheet metal, that sheet metal could be bent with a pair of pliers. I have done such before, here and there.
Now - if this looks possible for you, bend it as near to the truck as possible (away from the coupler), and bend it only a little at a time. The coupler itself cannot be bent, as it is die-cast and will break. I do not recall the exact relationship of the mounting plate and the coupler itself.