Yes, it's not like any other blade you encounter.

With the arm pulled away and pointing toward you, flip the blade so that the wiping edge is against your chest.

Then with your left hand pull the blade to the left (no spring to depress).

It will be difficult as it is likely gummed up with dirt, but if you are pulling in the correct plane, it will just slide off.

Then you can see how simple the attachment mechanism is.

Putting it back on should be a breeze, but you have to again push in the correct direction to make it seat properly (no reassuring clicks like on front wiper blades).

Doesn't look like you can just refill the rubber unless you were very innovative, so probably a dealer-only part.