It's pretty easy following the instructions, I think there is 3 different options depending on what you want. I did 12V with both batteries in parrallel. I didn't reuse the battery cables, I made new ones, and I removed the drivers side alternator wiring all the way back instead of just folding over the ends. Only problem I encountered was brittle wiring that didn't like being rebent so it had to be replaced. I also didn't have a condenser on my passenger side alt, which was supposed to be removed. Any questions, just ask.