i did it myself. took a couple of hours. about a 7 on a scale of 10 for difficulty. the part cost me a little over USD 100 at today's exchange rates.
the guy at the parts desk said that sometimes they take them apart and clean them and re-grease them which works but i couldn't see how to get the thing apart and wanted to get it done quickly.
a guy name youry here started a couple of posts where i put some pics so you can see what's involved if you feel like doing it yourself.