Ground Point RE Repair Wire, Terminal Size, De-Pinning

I am in the process of adding a 12V accessory outlet to the rear of the car right below the RE ground point.

I am planning out how I am going to wire the circuit and noticed that the RE ground point terminal has three empty spaces.

I can't figure out how to de-pin the terminal to measure the terminal size and find a repair wire I could use to add my ground wire through butt splice.

The questions I haven't been able to answer are:

1. Is there a list of part numbers for repair wires for the RE ground terminal?
2. How do you de-pin this ground point terminal? There is a retainer clip but since it is a ground point it is hard to see what the locking mechanism for the terminal and housing looks like.
3. What gender and size are the wire terminals?