For $20, you can get a three day subscription to the GM / Delco service website for your VIN. Here's the link.
https://www.acdelcotds.com/subscriptions#
This is what the techs use (or should use) to do all repairs. It will give you step by step details on how to remove and reassemble things, including torque specs. Also, if you have the capability you can print the instructions to PDF and save them for future reference. Over three days, you can troll through all the repairs you might do on your truck (brakes, suspension, etc.). I've used this a couple of time when I'm working on the truck. Definitely allows you to plan your method of attack!
if you need parts (i.e. a broken clip, lost screw, or anything else for the truck) you can find it at the following website.
https://www.gmpartscenter.net/auto-parts/2017/gmc/sierra-2500-hd/denali-trim/6-6l-v8-diesel-engine
Hope this helps.