It might be nothing more than loose bolts. Check them first, I seem to remember one or two posters finding them loose. You'll need an 8mm wrench.
The recommended torque is just 9 Nm (6.64 Ft/lbs), little more than hand tight, don't overtighten.
If you need to replace the gasket the cover is nothing more than a cover, there's nothing attached to it and it comes off easily for gasket replacement. A new gasket is part number T1260969.
Last edited by Forchetto; 11-11-2012 at 11:03 PM.