Bachmann anniversary 4-6-0

[borduas]

The pilot truck on my 4-6-0 is broken. This is the older version slot type. I have the replacement now and am trying to figure out how to get it apart to remove broken truck and install new one. Expected it would just be a matter of removing front part of bottom chassis but on careful exam doesn't seem to be the case. Have looked at exploded parts diagrams but aren't helping. Can someone out there who has experience with this please help. THs