I have added comments to steps 5, 6, and 7. The biggest piece of advice is just to make sure you have all 20 screws removed before trying to remove the keyboard (the guide does NOT mention all 20 of these screws). This might be more than necessary but I felt safer removing them than risking snapping one of the plastic clips that holds the keyboard in place.
When reassembling, gently push the cable into its respective slot. Each cable has a white stripe on it that should line up parallel to a white border on the motherboard. Each slot also has a very delicate locking hinge that will secure the ribbon cable in place. One the white stripe and white border are lined up, you will need to close that hinge to secure the ribbon cable. Try testing your battery and keyboard before fully locking the keyboard back in place.
In step 5 I noted that I removed 20 screws total. I was not able to pry off the keyboard until I did this. Be very careful and do not force it. I was not able to remove it with a spudger because it was too thick. A credit card worked well because it was thin and you could slide it carefully along the plastic clips to safely disengage them from the case. Note that your credit card might be damaged in the process so use an expired one or a similar plastic card.
In total I removed: 10 screws from the outside of the case, 3 small screws around the optical drive, 4 screws around the hard drive (remove the hard drive after doing this), and 3 screws near the SSD and RAM which have little triangle arrows on the panel nearby. I was not apply to perform step 6 until this was done.
