Take a look at your car and you'll see the diagrams aren't even necessary. The screws are very obvious, the most important part about the removal is the order in which you remove the trim.
Lower, upper, then the rear deck.
The upper C Pillar trim screw is behind the Airbag badge, use a small screwdriver to pop out the badge to access the phillips screw behind it. The rest of the Upper C pillar is held in with clips. Getting the Upper C pillar trim installed correctly can be a pain, the clips that hold it in can be hard to line up.
I'd give this project a difficulty of a 5/10.