Originally Posted by Diesel911

Below is not an exaxt pic of your differential. but ounce the Flex Disc is removed you will find some sort of nut holding the 3 pronged yoke on. You need to remove the yoke and maybe a spacer washer in order to get the seal out. Please besure to not how the spacer washer comes out.

I do not know the details but that spacer washer or one further inside has something do do with the asjustment of the Pinion and the Ring Gears.
If there is no DIY on it I would suggest waiting until someone who has more info can advise you.