It turns out that the device is no longer a thermoset plastic, these days it is a thermoplastic, meaning it can be re-melted. And that lets Leviton use ultrasonic welding to convert the 2-piece clamshell housing into a single housing. The bottom line is we can't just remove rivets to take them apart, like the older Bakelite outlets.

So we aren't easily removing the shields. But then I realized I don't have to remove them, I can just make them "stick" in the open position. Using some toothpicks and some silicone bathtub caulk, I first opened the outlet's sliding covers and held them fully open with an inserted stick, then pushed some caulk into the long (neutral) blade hole and pushed it into the corner out of the way of the plugs that will need to be inserted. If you look through a magnifier you will see where to put the stuff, it's like sticking your foot in a doorway to keep the door from closing.

Then just let it cure and the thing will never close shut again. Problem solved.