Rear Window Wiper Blade: Removal

Unlock spare wheel rack and move it clear of the rear door.
Raise wiper arm off the windshield into the upright locked position.
Pivot the blade until the locking tab is exposed and then press in.

Fig 1: Exposing Locking Tab
Courtesy of KIA MOTORS AMERICA, INC.
Push wiper blade down the arm until the hook has separated from the blade.
Now slide the blade up the arm until it clears the hook.