Electric kettle with faulty on/off switch (Pokesdown BH5)

I have a Bosch electric kettle, and the on/off switch has become faulty. It won’t stay switched on, i.e. pressed down, so the water can’t heat up.

It might be something quite simple, but I have bought a new kettle now, so if anyone is handy with electric appliances and would like to have a go at mending it for their own use, they are welcome to have it.
Otherwise it will have to go to the tip, which might be a shame if it just a simple fault.