I believe the bonet catch can be acssed by pushing the drain tube out under the wing and using that hole. Still a bit of fiddling

 

When the hood release cable on my previous 2005 S-Type snapped a decade ago, I was able to open the hood by jacking up the front end, removing the front undertray, and reaching up with a long screwdriver to pop open the latch. That was on a rear-hinged hood. With the XK8/XKR being a front-hinged hood, this approach would be much more difficult if not impossible....

 

I think you are only able to do it if you drill a hole in the wheel arch. At least that was what I have been told. The rear boot is similar although you need to take out the headlight and go in that way with a very long screw driver. It's not a very good time by the sounds of it.