(Not sure if it's the same on later models or other Jags).

As you may know, there are three bolts holding the rear light fitting cluster in, and as you may know, there are a couple of Youtube videos showing you how to remove the fitting. All tell you to remove the three 10mm nuts. The one on its own that's furthest away is a bit of a pain to get to if you want to remove it. But...

YOU DON'T HAVE TO!

That third bolt holds a clip onto the body of the car. If you undo that nut and remove all three, the clip stays attached to the light cluster. But if you ignore the third nut and leave it in place, it holds the clip onto the car. Once the two rearmost nuts have been removed, the whole light fitting slides right off the clip when you pull it (the fitting) towards you from the back of the car. Refitting it is just a matter of pushing it back in and replacing the two nuts. 

In other words you only need to remove the 2 nuts at the back and the whole light fitting slides out - no need to even touch the third one.

Hope this helps somebody, I just replaced my reverse lights for brighter LED ones. 

Great to know, thanks for sharing!