I like that idea to use a battery to heat a stud. Never heard of that before. I would guess most of heat would be right at the threads in the block....
He didn't provide the correct electrical connector either. The AC Delco / Delphi pump seems to be good. It was one of few brands that published a Max...
I must admit I've pulled relays without disconnecting the battery but my relay pulling tool is safe for that but now that I have a battery disconnect...