tried changing the oil in my ird and found that the oil really smelled bad, like rotton eggs, bit of metalic swarf on the drain plug aswell, does this indicate that it need changing, anyway, problem is i cant get the nut out to refill, the head is slightly rounded and i tried alsorts of tools but i cant get much leveredge under the freelander, any tips on how i can get this nut off, i cant drive it till i sort it, any help guys.