I'm replacing the starter on my 2001 softail fatboy efi and I'm told that I need to remove the drive train case to remove a bolt attached to the starter. My question is do I remove the small case or the entire case that goes over everything to remove this bolt? Any help would be greatly appreciated. Thanks.

 

Remove the outer primary cover. The big one on the left side. Then to get to the rear starter bolt remove the oil tank bolts and get a long ball end allen socket and wiggle the oil tank around so that you can get to that bolt. No need to remove the entire oil tank with the right tools.