This video is a run down of the some of the struggles I ran into when changing my rear shock seals on my 2019 Stumpjumper. The fox website acutally has really good instructions on how to do this. So feel free to skip on over and follow those.
If you have a stumpjumper or a bike with a Rear Float DPS shock, then this might be helpful for a first timer to see what problems I ran into. The sealkit for this comes with everything you need. I even had extra o-rings left over which was fine depending on which shock type you have.
Fox Link: https://www.ridefox.com/fox17/help.php?m=bike&id=570
Fox Shock Service Kit Part ID: 803-00-142