I imagine you've removed the snap ring at the front end of the shaft that retains it. Other than that, I'd use heat and ice alternating... As well as penetrating oil. Seized shafts seem to be a very common problem. Take your time and it should submit. Once it starts to move, you're set.I can't figure out how to grease the cable and the drivers side wiper shaft is stuck in the brass pipe.
I don't recall removing the cable, but it looks like it should come out once the nut and block is removed from the D/S end of the cable.