I have had 2 go on me,the 1st time I got one from the scrap yard, but this time I took off, really easy to do if you have some nouse, opened up the workings via 5 screws, took the arm out cleaned all the rust off with wire brush, greased back up replaced in housing and now runs like a dream. Apparently it is a manufacturers fault whereby water runs down the spindle into the housing and can not get out and so corrodes the mechanical arm. Take the cover off the hatch, there are 4 plastic screws that just twist out using a screw driver, when you have these out the cover is held on with popper type clips, get your finger under the cover and force off, they are quite strong! When you have the cover off you will see the motor, take the wiper arm off 1st using a 13mm spanner for the nut, again the arm will be difficult to come off the tapered splines but once you get some movement it will come easily. When you have the whole wiper off you can then take the motor off which is held by 3 bolts 10mm socket I think, the earth is connected to one of these, when all off the whole unit will pull off with the shaft out of the window. You can then undo the 7 or 9 screws which hold the body together and split the lid, you will then see the workings which you can clean in white spirit, the toggle arm and spindle will come out of the body which will make cleaning easier and you can get all the rust off the arm, when all clean and you can move the toggle hinge easy, pack with grease replace back into the housing and bolt lid back up, refit as above in reverse. Hope this is not too much gobbledegook but thats how you do it, happy stripping!!