dean you need to take the air filter cover off and then undo the nut at the back behind the round plastic cover,you will need an impact gun to undo this i expect or you can get someone to hold the back brake on and see if it will undo with a ratchet.also take the dipstick out and then tilt the cover ouwards at the botttom and then pull it off.if you turn th engine at all with the dipstick out it will chuck oil out the filler hole so put some paper or card down on the floor unde it.
adam bike doctor
July 2010