I just installed new Mazda inserts in the wiper blades. It only took a couple of minutes.
Lift the wiper arm. Press the square push button on the arm connector and release the blade from the arm. Pull it off.
The plastic knob thing on each end of the blade has a space on the bottom. Pull the rubber insert back (compress it into itself) until the end of the insert clears that space, then slide the insert off through that space. (It's easier to do than to describe.) Slide the new insert back into that space and into place. Click the blade into the arm, lower the arm. Done!
The Mazda part numbers are TK7867333 & TK4867333. Most the on line dealers want too much for shipping, but one on ebay was reasonable. $20 for both, delivered. There is no dealer convenient for me to drive to.