12 Volt Conversion

[Muttley]

Dad is wanting to convert electrical system in his Coupe to 12 volt. I've done a couple of searches here but the only things I come up with are posts saying "do a search" or "why would you want to do that?". Does anyone have a simple diagram of which wires need to be switched/replaced/run to complete the conversion? And please, don't clog up this thread with "WHY?!?!?" or similar posts.