I think this has been shown before but thought I'd add my experience installing the set of cliffys. Overall, took about 20 minutes for the sim card hole and 20 minutes for the scoop.
Sim Card hole: Remove the two screws (circled in red) on the ramp flap and lift the ramp. You can rest the ramp flap on the QED guy (you want to make sure the QED guy is about an inch away from the left side so the ramp can clear. I circled the bottom of the ramp flap in the picture because when I was done, I put a piece of mylar for the ramp to rest on. That ramp flap is sharp and I was afraid it could dig into the playfield over time.
With the ramp up and out of the way, remove the rubber on the two posts, then remove the posts and left screw circled in red. Loosen the four screws circled in blue. Everything can be done from the top. The right screw circled in blue allows the cliffy to slide under the metal ball guide. There is not a lot of gap even with that loosen, but eventually you'll get it slid under. I wrestled with it a bit. The back two screws are loosened to allow the 2nd piece of the cliffy to slide under (cliffy's set only has two pieces, i think the factory has three pieces). That's about it, reinstall and tighten everything down and you are done. it was a perfect fit on my game.
Remove the plastic behind the phone, it's held on with one screw (circled).
Remove the two nuts holding the phone bracket (circled). Phone can be moved out of the way, no need to disconnect any wires.
Remove the rubber and the two posts, these must be done from below as they are held on with nuts. I had a hard time getting the right one out and had to use a hammer and nail set to punch it out. Once removed, cliffy slides in, reinstall everything
I also installed the switch slot protectors and the skill shot protectors, they just pop in. Note that I do not adhere them to the playfield, they lie flat as is. next up is the shooter lane.