Of the four can grounds, two don't connect to anything else on the PCB, and the other two connect chassis grounds, which there's no other path through.
Folks who do nice restorations will pry open the can, scrape out all the gunk, and stick the new caps inside, so it looks 100% original.
I do not care this much. I stuck the positive leads of the caps in the right place, and the negatives wherever they fit, which meant two leads ended up sharing the same through-hole.
Then I used a bit of scrap wire to connect up all four negative leads.