does anyone know how to remove the shell of the locomotive?
First, be aware this is not easy.
1. Remove the rear wall. By gently spreading the back of the shell, you should be able to pull out the back wall. The door cushion make fall off as well, but it pops back on easily.
2. Remove nose plate. Under the nose, just in front of the front truck, there is a plastic plate that will pop off using a finger nail or jewellers screwdriver. Go easy. It is held in place by plastic tabs, but they seem fairly sturdy.
3. The hard part. You can release the frame, by spreading apart the shell. Again, go slowly and gently. This will take a while. When I did it, I accidentally popped off the stirrup steps. Luckily, they didn't break or get lost, and I was able to glue them back on.
Before you attempt this, perhaps you could let us know what's wrong. Perhaps there is a solution which doesn't require removing the shell.
Regards,
Jonathan