the abs sesnor is trypicall held inn place by a 10mm headed bolt, which will most likely snap off.
the sensor itself varies from £30 to £60 depending on age of car.
the wire from the sensor goes up into the wheel arch, so the wheel & arch lining will need to be removed, & then the wire disappears up thro the wing & back out at the top of the suspension to a whit eor black connector.
tie a string to the old one when pulling it out
wheel off, open the 'long' bolt thro the lower wishbone [ 19mm ] then open the 177nut & split the ball joint, also open the 17mm drop link [ you may need to jack up BOTH wheels to take the weight/strain off the arb ] & then the 4 17mm nuts on top.
the upper wishbone is connected to a bracket which will be held to the 2 bolts on the strut by TWO O-RINGs ....t hes eo-rings need to be rolled off the bolts before you cna seperate the 2 parts.
the very long bolt thro the wishbones [ 17mm ] can be removed with the wishbone off the car, just rem the correct orination of the head [ spring ] side
use copper grease on moving parts