'70 Dart wiper blade removal

Hey all,
I know this is a stupid question to everyone on here, and I've been changing wiper blades for 30 years now, but I'm confused as to how you remove the wiper blades on my '70. Not the whole wiper arm, just the blade. (I didn't see any other threads concerning just the blades.)
The Dart service manual makes it appear that there is a "pin-type" attachment to the wiper arm but that doesn't appear to be the case with mine. As you can see in the photos below, there's a bendy-tab right below the wiper serial #, but when I press it and try to pull the blade off nothing happens.

I just don't want to break anything with my freakish super-human strength :rofl: Does it pull straight off the arm when you press the tab? The replacement blades my dad got me are new production but similar in appearance of the attachment. I feel very silly having to ask this

DartWiper1.jpg DartWiper2.jpg