Re: Moding a 59' neck.
That video is ok, but I need to stress the importance of knowing which wire is which. In that vid, he is using a pup with two slug coils. Your pup ('59) has a screw and a slug coil.
On your pup, the coil wire that is connected to the ground is the "start" wire of the screw coil. That will be soldered to the green wire in your cable.
The other wire of that coil (which connects to the two coils) is the "finish" wire of the screw coil. That is the wire that should be cut to separate the two coils (like the red wire in the video). That will be soldered to the red wire in your cable.
The remaining part of the wire that connected the two coils that you just cut, is the "finish" wire of the slug coil. That will be soldered to the white wire in your cable.
The last coil wire is the "start" wire of the slug coil. That will be soldered to the black wire in your cable.
The bare wire in your cable is the one that is soldered to the baseplate.