Loco Art How To Modify An Existing Train?

As the title say, if I have to add a safety system to an existing train, what I need to do?
The steps involved are something easy like make a simple repaint?
Or I have to edit/recreate by myself some files due the new integrated safety system?
As I suppose it's the second one the right way to follow but, exactly, which files need to be edited or created?

There's a tutorial about this?

 

You would need to remake Simgraph for the train which is very difficult.

 

Unfortunately, moofers#8902 is right. To integrate it with the normal controls, I think you'd have to make a whole new Simugraph. With all of the different variables, it would be virtually impossible to wind up with a rail vehicle that drives the same. Cosmetic changes, by comparison, are relatively easy (Though I know that's not what you were asking about.)

 

Ok, so the first step Is make a repaint and if it work, then create a new Simugraph file to substitute the original.
I'll also have to add the new control in the event graph right?

 

I hope you know what you're doing because its not well documented.