For 2006 and older, the input shaft speed sensor is up front, left front corner of the transaxle. Starting on the left front wheel, loosen the lug nuts, jack up the vehicle, and place it on the jackstands; then remove the left front wheel. Depress the release tab located on the input shaft speed sensor and disconnect the electrical connector from the sensor, remove the mounting bolt and the sensor, extracting the sensor O ring. The installation takes the reverse order with a new O ring and mounting bolt is tightened securely. The output shaft speed sensor is at the top of the transaxle; undo its electrical connector, unbolt the mounting bolt, lift the sensor straight up and discard the O-ring, then reinstall as before. On 2007 and later models, both sensors are on the transaxle front. Then remove the engine splash shield, raise the vehicle and secure on jackstands. On the input shaft speed sensor remove the O ring, disconnect the electrical connector from the input shaft speed sensor, remove the mounting bolt and take out the sensor. The reverse of removal is again installation, with a new O ring and the mounting bolt really, really tight.