simple. done mine yesterday, tried tapping with hammer, stunning the old blade with sharp shots from the spanner, wd40, ac-90, bit of penetrating oil. Pulling hard .
Nothing, absoloutely nothing,
Sweared some more.
Then tyried pull hard but slowly one way, ie backwards, then push it back hard but slowly the othere way, then they just ease off, noth were off in a second, now i have lovely aero wipers, ta da.