Pretty sure "NB" is nota bene or "note well".
Putting the bucket back on is essentially the reverse of taking it off. Drive into position, lower the loader arms until the holes line up and put the pins in.
Of course, you'll wind up moving the bucket around a bit to get exact alignment. My bucket on the JD was light enough I could (usually...) do it by hand, but for a larger/heavier bucket you may want a bar handy to tweak the position.
Loader arm pins first, then pick the bucket up so it pivots on the pins. Extend the curl cylinders until the holes line up or nearly so, then rotate the bucket on the loader arm pins for final alignment.
If your curl cylinders are cross-coupled, you'll find that extending one side makes the other side retract. Just pin whichever one is closest in place and then manually move the bucket until the other one lines up.