I want to convert this auto/dent removal spot welder to make batteries with. I got it for $80 and seems to work fine.

I think i need to do the following tasks:
1) Replace the leads
2) Attach handpiece
3) Get handpiece to trigger the weld

I got one of these: https://www.amazon.com/Shkalacar-Integrated-Welding-Automatic-Accessory/dp/B09BFQ7HC3/

I realize I'm not sure how the triggering works. Before I start taking shit apart, anyone have suggestions on this project?