Originally Posted by sagebrush1976
2007+ Fatboy fender is a direct bolt on. You'll probably have to do some wiring extensions for the taillight but that's it.
I put a Fatboy Lo fender on my 2008 Crossbones which I am sure has the same back end as the Train and I didn't have to extend the rear harness. It was plenty long enough. What you do have to extend is your turn signal wires so that you can plug the left turn signal into the right turn signal plug and the right turn signal into the left turn signal plug.
I did a write up for my swap. I believe that most of the info should be relative to your project since I am pretty sure that the Train and the Bones share the same rear end.