A fellow club member has given me a Bachmann 2-8-0 outside frame consolidation to repair. (Cat # 81299) The gear on the drive axle had split.  He obtained a replacement and asked me to fit the gear.  This was the easy part.  The problem I have is that the motor and gearbox appear to be jammed. The motor hums but does not run.  (This is without the final axle gear installed).  I need to remove the motor and gearbox to check it out.  I have the parts list PDF but no instructions on how to remove the boiler,etc to be able to remove the motor and gearbox.  Is there a manual or instruction sheet available showing how to gain access to the motor and gearbox?  Any assistance would be greatly appreciated.