mine was extremely tight and hard to get off after one dealer had done it up far to tight.
there are two marks and an arrow and the arrow should be between them, but the dealer had tightened it passed it!
anyway, to undo I had to very carefully used a screwdriver, I did NOT use the head of it, I used the long body of it so to speak (the bar!) and put it in the grove and with the extra leverage I managed to undo it!
remember RIGHTY tighty, LEFTY loosey! (so turn it left/anti clockwise!)
lol