Meridian
The drain plug for the bevel box is a hex head bolt, lower down on the rear face than the socket head bolt. The socket head bolt is the level to which the factory fill, and not the orange breather to which many people myself included fill to. This may explain why you did not get any oil out. I change my bevel box oil every year at the same time as the engine oil. I am able to do it without jacking the car or removing the seats. I remove the boot liner, I can then reach under the car to the rear of the bevel box using a socket on a short extension, undo the drain plug. I then reach in though where the boot liner was and undo the orange cap, I have thin arms, and refill using a syringe attached to a length of plastic tube. Complete job takes less than 15 minutes.