according to the manual, and my own observations after removing a wheel, the ABS sensors seem to be retained by a single, 8mm head, bolt.
My guess is that the sensors are Hall effect transistors that sense the passing of "teeth" on the cog wheel. Is the place where one can get a dirt build up, between the sensor and the cog wheel? If so, does removing the small bolt allow you to get to the sensor itself and clean it up?
There are no signs of damage to the wiring, which seems pretty well protected, so I'm hoping a clean up may do the job. If not, I suspect that the sensor and its wiring come as an expensive unit
P.S. will you be at the final GP in 10 days' time?