10 bolts on the center carrier
use a jack to break the seal between the carrier & housing , it helps to lower it too
while you have the axles out repack the brgs with grease , they do not get oiled from the diff
a 489 "should have a floating center pin inside the diff , if so you are ok , if it has a 4 pinion sure grip unitit will have 2 "buttons that will fall out, these need to be in there to set axle end play
the right axle has a threaded collar on it , this needs to be tightened until virtually all end play is gone , I generally hit the right axle with a hammer to be sure the brgs are fully seated them check the end play again , it should be .008 -.018 end play , there is a hokked lock tab to install to keep the adjuster in place after the end play is adjusted correctly