The ABS sensors push into the hub from behind through a circular cutout then are secured by a 10mm headed bolt, they should just pull out when you undo the bolt but inevitably they are crudded up with brake dust road grime etc and are very very tight. The fact they are made from flimsy plastic means you can't just lever them out but need plenty of penetrating lubricant and take your time working them a couple of mm anticlockwise then clockwise using asmall tapping hammer or similar until they loosen and pry them a small amount at a time away from the hub.
If you try to do it too quickly they will snap the plastic.
Some manufacturers put a connector on the cable so you can leave them in the hub when removing - another good idea not adopted by Fiat.
If you try to do it too quickly they will snap the plastic.
Some manufacturers put a connector on the cable so you can leave them in the hub when removing - another good idea not adopted by Fiat.