I’ve searched, and found the question has been asked before but never saw an answer that I understood. I am installing decoders in two late model SD70MAC HO Genesis Athearn locos. I have removed the couplers and coupler boxes-should the bodywork come off the chassis, or am I going about this the wrong way? A very frustrated model railroader awaits your help. And just so you know up front, I’m not overly bright so clear instructions would be greatly appreciated.
Thanks for your help.
Jim
I dont have the engine in front of me but as I recall there should be 2 sets of tabs that you can see on the underside of the loco. Those will need to be pressed inwards while you pull the body upwards…
Stomping on it will work also but there is a little glue involved afterwards. [:-^]
You might try their website forums.
Athearn don’t got a website forum.
As I recall, the shell was pressfit on there with the couplerbox screws. Best thing I can tell you is to hold the chassis by the fuel tank and tug on the carbody. If there’s pull, then I’m right and you just need to work her carefully off. If it don’t budge, then I’ve forgotten a screw and you need to probe around where it’s resiting and see if you can find it.
The tabs turned out to be the trick. Remove the couplers and coupler boxes and slide them out from the pilots, then take a very small and thin screwdriver to help disengage the tabs by pressing in on them from the sides. The tabs barely stick out of the bottom of the frame, under the trucks between the second and third inboard axles. Hard to see and hard to get at.
After you are done and put the shell back on, get the glue and start re-installing the parts that fell off while you were tugging on it.
Thanks for the help.
Jim
+1 for me 
LOLOL.
HF1[:-^]