As long as you install the yellow wires to the same terminal block where the originals go, it doesn't matter which yellow stator lead goes top or bottom. Yea, those flywheel nuts can be a booger. A good impact will remove them easier sometimes ,but make sure you have it set to loosen and not tighten as to not over torque the nut. I actually recently went contrary to what I would advise on here, and used a suitably sized screwdriver between the starter bendix teeth and the flywheel teeth as a backup and used a long handled breaker bar on my engines flywheel nut. Mine came off surprisingly easy this way. I also used an assistant to steady the screwdriver while I pulled smoothly/not jerky on the breaker bar. Not for the faint of heart though.:joyous: Of course I wouldn't want to feel responsible for teeth that could conceivably break off of your flywheel in trying this, if you get my drift.
Otherwise some type of long handled flywheel spanner would be necessary.