The first lug is the bolt that goes through the main board here (with a black metal strap)
That would be your NEGATIVE side as that is your torch
Then the second lug would be here as that’s where your work clamp goes
Takes but maybe 10 minutes with the most time consuming part being the removal of all the screws; ensure to set aside your parts in a manner where you know what goes where
I went a little extra and wired up my own port to quickly connect and disconnect on the backside of my machine as I didn’t want wires hanging out when using my plasma cutter away from my table