I've never owned a model train before but I bought a Disney FastTrack Christmas train in 2020 for the grandkids.  Has worked great until this year.  I have a short somewhere in the locomotive.  I am trying to remove the body from the chassis so I can look for an obvious short (bad or frayed wire, something out of place, etc.).  I cannot figure out how to remove the body.  I've removed almost every screw I can locate.  I've loosened the body but can't pull it off the chassis.  I don't want to get too rough and break anything.

Is there a secret to removing the body?  I've searched YouTube and even spoken to tech support at Lionel but no luck.  Any help is appreciated.