Literally just done the fronts on mine. I felt there was no chance of removing the sensor in one bit and in any case I knew mine were useless.
Had to remove brake caliper and disk. Once removed you can get access to a few mm of sensor on the other side of the knuckle. I smashed the sensor into two parts with a hammer and screwdriver. You won't jam the disc end in as that part is not wedged. The wedged part is the bit in the steering knuckle. You will then either have to drill that part out of the steering knuckle or knock it out from the disc side. In fact it was in too tight to drift it out and I ended up smashing it out. The access is tight and you may put a small dent in the splashshield but it's doable and as long as you aren't wreckless you won't damage the knuckle. You'll then have to fish out the disc end of the sensor. It will be very loose but fiddly to extract. About an hours work a side including installing the new one.