Just about the same technique I used to hook up my first LCD. If you guys saw the way I hooked my first up you would probably ban me.WARNING: DO NOT DO THIS, SPOCKs GUIDE IS MUCH MORE PRETTY.
1) Cut printer cable in half and continuity tested every single wire to every single pin, used masking tape to record which pin what wire went to.
2) Used a grinder in the shop on an IDE cable almost down to the where the plug interfaces with the cable so that it fit into the slot, but didn't screw up the connection from the wire to the connector.
3) Twisted wire pairs together, dipped in flux, soldered together, electrician tape shielded!.
Noone said I was a pro like you guys or anything.
What types of supply houses can I look for for raw materials so I don't have to halfass my 3900