there is only 1 bolt holding it on, it needs an allen key to remove it. then you have the problem of actually getting the sensor to come off as it will no doubt be seized in position due to years of brake heat, rust and dirt. once removed you need to disconnect the wiring harness clip. then fit the new one and be sure to measure the gap between the sensor and the hub because that gap is what dictates the strength of the sensors signal and it must be within a certain range. use haynes to get the gap range, and use a feeler gauge to check it.
