Do the heavy wire first then the small ground wire (to reduce wire stress) then the plug in harness.
The nut on the back of the pivot bolt is next hardest. You need to get the nut on a few threads then use a ratchet on the bolt head at front while holding the nut with a socket and extension. I positioned myself with feet facing front of car (car not way up on a lift just on 15" ramps) and looking at the pivot bolt nut. Snug the pivot bolt then adjust the belt tension and final tighten the pivot using the front bolt head.