you are correct...it's on a spline...when I removed mine I just grabbed the crow part of the hammer and at the same time I would pry I would wiggle it back and forth...eventually it came off.....just make sure you mark the wiper so you know where it was originally.....when I did mine I put a little too much on it and it popped right off and then when i put it back on it was worse than before......becuase i didn't mark it......but you can basically eye it up w/o marking it....
it's really not difficult.....let me know how it works out.
later
slingersvt
