Follow the ABS wire from the abs sensor into the hood of the car. its an orange plug. 2 prong. use an ohms meter. compair the front left and front right's read outs. the rear abs you follow the same way. believe the connector is actually on the underside of the car. if one is dramatically different than the others, that is an easy way to figure out which one needs to be replaced. that is how i did it on my gsr. if you have access to an all data, look up the exact proceidure in there.
good luck
-Steve