"IT" doesn't exist in the service manual. However, if you go to chapter 9 and get to the diesel section you look up the part about R&R the gear case cover, and that will almnost walk you through it.
There is a lot of GREAT info from many people on this subject here.
Grab a cold one, sit down at the computer and search for KDP and peruse a lot of great info and links! Including part numbers, pictures, tools required, etc etc.
This club is the BEST $$ ever spent on my truck!!.
Dan