Who says Jaguar mechanics don't have a sense of humor?
Changing the Differential Oil
Drain the gear oil out the plug on the bottom of the differential. Use a socket that fits the square plug snugly. Then to get the new oil in, take the spare tyre out, remove the carpet liner on the back of the boot. You can then see 2 metal plugs in the boot. Pry out the one that lines up with the differential. Use a half inch drive extension to remove the plug in the diff.
WARM UP THE GEAR OIL in hot water and use a tube on the end of the squeeze bottles the oil comes in to fill the diff until the oil pours all over the garage floor, scream, and jam the plug back in while getting the oil all over the trunk.