Harvey is right, there is a couple small hex screws that hold that wiper arm on and they are a PITA to get at. If you can at least get to one and loosen it, you may be able to get the arm off at that point. I believe there is only two set screws, and one was a little easier to get at than the other. In my case, I couldn't really see it, and had to do it by feel. Perhaps with a small mirror and bright light you can at least find where the screws are at if you can't feel for them. Then finding the right allen wrench to fit in the grimed up set screw's hole is just as pleasurable! Good luck. Just plan on taking some time and have patience. :| Colby