No pics but it's dead simple.
1. take off the switch cover (2 screws on back of spine).
2. Remove cable from switch and neutral connection.
3. Slide protective shroud down from broken area.
4. Measure the length of cable between broken cable and terminals, less than the area between grey insulation and terminals.
6. At the broken point CAREFULLY cut through the outer insulation ( I use a Rabii tool but in carfull hands a stanley knife will do).
7. Pull off the broken bit of outer insulation.
8. Measure the blue and brown wire. Add an extra cm and cut.
9. Carefully remove about 1cm of insulation from blue and brown wires and twist the copper together tightly and bend the copper in half and crimp on new terminals. Terminals are cheap as chips if ordered from China, however, I would recommend a proper crimping tool. A pair of pliers/mole grips is just not good enough
10. Re-route the cable and make sure the switch is in the "ON" position before fitting the the switch housing.