If you want to ground the cabinet exactly as shown in the service manual it looks like this:
The ground wire from a 3-prong AC power plug (blue wire in this photo) connects to the screw with the green wires. Or you can use the original 2-prong plug and run a wire from the ground screw at the back of the cabinet to something like a water pipe outside.
The green wires attach to a connector which plugs into another connector near the power supply unit.
From this plastic connector, there should be two green wires that terminate in metal loop connectors and a third with another plastic connector. Attach the first wire to the back of the cash box screw. Run a separate wire from that same screw and attach the other end to the screw on the metal plate that supports the foot in front of the power supply unit.
The second longer wire attaches to the coin door hinge screw. Attach a separate wire from that screw to the screw under the coin mechanism.
The third wire with the plastic connector routes up to the control panel and plugs into the metal bracket next to the button connectors.
From there you need another wire that plugs into the other side of the metal bracket. The other end attaches to the screw on the side of the coin chute. Run a separate wire from the coin chute screw to one of the control panel carriage bolts.
There should be additional wires attached to the left and right instruction holder bolts. I don't have those. I might add later.