Here's my G707 in bits.
I'll start with the sleeve that fits in the headshell end of the tonearm. You can't get this out without removing the headshell. Unfortunately the headshell is glued to the tube and may break when you try to remove it. Mine was already broken when I bought it so was of no consequence.
Here I've threaded a wire up the armtube so I can pull the ground wire in.
And here"s the arm ground sleeve pushed back in.
And here's the other end of the ground wire that will do down into the arm pillar and be soldered to the din socket.
That's the ground sorted for the armtube so now I'll go to the arm pillar and the ground connection for that.
Here's the arm pillar stripped down.
The black wire is the ground connection for the lower half of the arm. We need two ground wires because the bearings may not have good continuity so the arm is effectively split into two parts.
These next shots shows the ground wire connects to the lower part of the bottom bearing spigot. There are some thin washers there that determine the height of the inner bearing ring.
And here's the pillar back together.
The black wire poking out of the bottom of the pillar is the other end of the ground connection. It goes to the same pin on the din socket as the other ground wire. You can see they are just long enough to be soldered to the din socket and will then be pushed back up into the pillar. I'll come back to that later.
The main problem with my arm was the top bearing you can see in that last pic. The dust shield had come away and a minute ball bearing has gone missing. I managed to find another and I've reassembled it minus the dust shield.
Back to the arm tube and the next pic is of the new internal wiring.
I'll leave it there for now as I haven't finished putting the arm back together. I might get that done this evening if I don't get called out