I think you're right.....found this video after posting:
Not sure if this would be easier than pulling an engine from a M60A1 battle tank

 

Just following up on my experience.
Bough the car on 3/3 with 53k miles.
Took it in to "meet the Lexus dealer" (as it had come from CarMax) on 3/14 to start the process.
They had the part about a week later but I didn't get it in there to happen until 3/28.
Got it back on 3/30.
Quick and easy. I tracked about 500 miles in the time I had it on Fuelly to gauge gas mileage. I'll be curious to see if there's an overall effect on efficiency but, either way, very low drama on the whole experience.

 

Just FYI, since my transaxle replacement I'm getting ~1.5 mpg better. Who knows could be a coincidental seasonal change in gas formulation. Could also be I never changed the tranny fluid like some on this forum suggest, and the fresh fluid is the cause. Either way i'm not complaining.

 

so everyone had a trouble free transmition update?

 

Yes, no problems at all. Of course, my old transmission had no problems either.

 

same here. Had no problems, but they replaced the transaxle during the recall. Still no issues.