One wire at a time. The small red wires go to the BMS all the other larger wires and straps can be wired at whatever voltage you'd like. Typically 12Vdc. These are probably wired as 48V in Jack's golf cart. Not really difficult to wire them up.
Yes Forest is right it' was wired 48v 200ah but you can wire it 12v 800ah. I built this for a family member and he's selling the golf cart so I took the batteries out before it's gone. These are aircraft type batteries and are coated in plastic, good for over 5000 cycles. I will take offers.