btw, if using the puller above, spray the wiper spindle with wd40 now before you go looking to buy one (time works wonders), then when you've got your puller, undo the nut a turn or two but don't remove it, attach the puller to the wiper arm with the spindle in the centre of the nut and apply some tension by turning the handle. When it goes tight and you can't turn it any more, tap the head of the spindle with a hammer and it'll shock the arm loose.