I just wanted to say THANK YOU!.... to everyone who's posted in this thread. I've been able to eliminate the "Pathfinder Sway" on my (new to me) 2001 Infiniti QX4, which *was* terrible.
Everything you need to know, to do the job has been posted already, but here's a little more, for anyone who's read this far. Two decent how-to videos are here:
Upper:
https://youtu.be/w2x5xJ0eLSY
Lower:
https://youtu.be/eMn9CjMcQZc
I used the Nolathane bushings and didn't have a press but here's a video showing how to install polyurethane bushes without a vise, press or anything but a nut, bolt and backer plates:
https://youtu.be/2jrlSiqLEKM
---NOTE--- The Nolathane documentation says NOT to put the grease on the outside of the bushing, but only on the area where the metal sleeve insert and interior polyurethane touch. INSTEAD, as lubricant they say to use a 1% soapy solution (Dawn + water). I found that spraying the bushing immediately before attempting to squeeze the components together made a huge difference. Also, I'd recommend a grade 5 or 8 bolt and nut for the job, since the pressure snapped regular hardware store galvanized bolts, on my first attempts. And, the thick metal J-bolt square plates in the Simpson connector section of the hardware store make good backers for your bolt head/nut; they are MUCH thicker than washers and are pre-drilled.
Here are the Nolathane part numbers I used: REV112.0006 (lower) and REV118.0032 (upper).
If I had it to do over, I'd just buy the arms with rubber bushings already installed, even if they don't last as long as the polyurethane bushings. I wouldn't call the job trivial swapping them, but cutting out the old rubber, cleaning the insert areas of the bars, and pressing the new bushings in, was, for me, the hardest part of the job. Don't be frightened by the alignment woes many other had; it's true that lifting the differential and using ratchet straps makes it doable. I'd add that a spud wrench or long tapered round chisel helps too.
Thanks again, ALL!