You could do it the Bill way, which is Trannyman approved... you'll see why.
I typically pull the drivers axle (working alone) or use a strap etc.. you don't need much, but that little bit. When you see the planetaries flush with the pinion, you are likely there. Sit your washer/bearing on properly and fit your diff cover in place. Now look at it from underneath and ensure it's sitting perfectly flush and not pushed out.
This means your bearing you glued in and the diff are in place correctly. Bolt the cover on with at least two bolts in opposite sides. Now wiggle your drivers cv unil you feel it's lined up and give it that little (engage compresson clip) thrust. When you know it's seated the output shaft into the diff you are good. Go put on your diff to engine bracket and swear at it while smiling about getting the job done.
FWIW the manual has you assemble everything, then put the output shaft into the diff and seat it. Essentially my way does that. Trannyman's info that you mentioned suggests the output shaft and drivers axle are putting pressure on the diff and then you seat it. Either way..you are seating the output shaft into the diff.
