Yep, same prob and WD40 didn't do it but a dremel cutter did, just be careful. Once you're thru the plastic insert a large screwdriver into the cut and twist, the arm should peel off leaving the aluminium ring. Repeat the process on this. The splines on the shaft make it difficult to remove, I even broke a clamp trying to use it like a puller. Definitely a design fault (or deliberate so you have to take it to a dealer?).
Chris D, January 2009