^This. I don't know how many times I've had customers (hell, I still do it) not remove the correct 4 bolts and sit there saying "why the hell won't this move?"
Once you've got all 4 bolts out (the correct ones) I take a small pry bar and lightly push on the nut from inside the oil fill hole and they usually pop right out without much fuss.
Once you've got all 4 bolts out (the correct ones) I take a small pry bar and lightly push on the nut from inside the oil fill hole and they usually pop right out without much fuss.