There is a diagram here for the Silvia, the light is basically in parallel with the boilers element....The Usual electrical caveats apply: If you dont know what you are doing, steer clear, these volts can kill you.
I dont know the Lucy, but If it has a Low water light I would be inclined to keep that....a pretty useful feature.
Just fit another lamp somewhere.
With Thanks to Randys wonderful site
http://home.surewest.net/frcn/Coffee/silviawire.html