I have a 1950-51 Lionel black gondola car for which I need to change out one of the trucks. It appears that I have to remove the metal undercarriage from the plastic part of the car in order to remove the existing truck. The metal part has four metal prongs that fit under four plastic retainers. I am at a loss as to how to remove the metal undercarriage without cracking or breaking the retainers. I have checked Greenberg's Repair and Operating Manual for Lionel Trains from 1945-1969, but cannot find the Gondola Car listed in the manual.
I would appreciate any guidance about how to change the truck on this car.
Thank you.
