So, for all of you curious folks...
I finally got time to pull the machine out of its cubbyhole so that I could get at it. To open the front of the UK Miele W1524:
0 Unplug the machine.
1) Open the door and unfasten the door seal from the front panel.
2 Remove the torx screw from the centre of the machine under the door. Close the door.
3 Remove the top of the machine by undoing one (concealed) torx screw at the front of each side of the top. Then lift the top from the front and disengage hinge-like lug sockets at the rear.
4 Remove detergent draw.
5 Lift the control panel assembly upwards. It sits on three plastic locating points. When it is clear, just rotate it through 270 degrees (from the bottom towards you) and lay it on the top of the machine out of the way. that way, you do not have to disconnect anything.
6 There are now revealed two torx securing screws - one each side. Remove these.
7 The front is now free to be removed. It sits on two locating platic lugs at the very bottom. Ease the RH one up and it will come free. Ease the LH side away at the top. This will expose a plastic housing with the door lock sensor cable. The housing clips into a locating clip and is very easy to just ease the top and the bottom of this away from the housing. I pulled out the door lock sensor plug so that I could remove the front completely and put it to one side.
8 Reassembly is the opposite of disassembly.
This exposes the element which is very easy to pull out and swap. I got one off ebay for 40-odd quid rather than the gold-plated one that Miele sell. Put all the fittings onnto the new element before you slide it in. Make sure the element sits in the locating guide inside the machine. An oily finger wiped around the seal and it will just pop in nice and easy.
Sadly, after changing the element - which was indeed dead - the bloody thing still doesn't heat up. I am wondering if the wee heat probe that sits in the seal of the element is dead as well. That is my next adventure. Anyone got any other ideas?