Thank you for this very well done step by step guide! I updated the RAM in this computer with no issues because of your procedure. FYI - I am a fellow Gaucho graduate way back from the Class of 1981.
Actually, there are only three screws attaching the motherboard to the case. The farthest screw to left in your photo with the red circles actually belongs to the hard drive connector. Each of the three screws holding the motherboard down actually have a white arrow pointing toward them on the motherboard. Please see your second photo with the closeup of the screw driver and you’ll see the white arrow located just left of the screw.
Again, thank you for those clear shots of the clear cellophane like tape. Initially, I thought I had to remove the black tape that was on the connector. That clear tape was nearly invisible on my computer and I probably would have messed up that connector pulling at the wrong thing.
Great that you had the second extra close up shot showing where exactly the two gray plastic tabs were. It was not obvious to me when I first looked at the connector on my on Acer.
I was able to skip this Step 7 because the antenna leads were long enough for the card to slide out after removing the retaining screw as shown in Step 8.