Thank you for the reply. It is much appreciated. Your responses sparked further items of inquiry.

Can the existing 4-sided slotted pinion nut be reused? If using the same nut, at least I would be able to mark the position and compare the old position with the new one for an extra level of certainty with the torquing procedure. I've read of people grinding down a socket to make their own 4-slot flange nut.

What is the staking (peening) you are refering to? I went though a Google image search and came up with this possibility,

taken from http://www.gearinstalls.com/charles/charles12.jpg

Is this what you are refering to? I do not recall there being a flat edge on my pinion output shaft. I also do not recall there being any of this type of staking on my slotted nut. Do you have a photo of what you are refering to grind off? I am not sure how keep I would be to do grinding inside the small opening of the yoke orifice.

You mentioned to tap with a hammer on the pinion nut [in the direction of untorquing] to remove it. With these nuts secured with >180 nm of torque, will tapping the nut, which is inside the yoke orifice and the striking bar will be at a disadvantaged angle, always have sufficient impulse force to remove it?

If I have the proper 4-sided slot socket, do I need to bother with any of this? I beleive I have located the proper socket for $56 USD.

Once the pinion nut is removed, do I need some kind of puller as noted in the FSM to remove the yoke?