These projects are very daunting initially, but I found if I printed off as much info as I could find, and I was lucky to get a very good CD for the GEN111 vehicles(Aussie versions), that it made the job a lot easier. I did my own wiring mods, and found the wiring diagrams I had made it so much easier.
So, really it means plenty of research, and print as much as possible.
Certainly the 2nd conversion would be so much easier.