Changing Vehicle Speed Sensor

My speedometer does not work at times, so I figured I would replace the vehicle speed sensor, so I have the new sensor, but does anyone have any experience changing one?.. I took a look under the car today, trying to find the sensor, and I found one plug on the front of the transmission but after unplugging it I saw that the connection was not the same to the one I have.. Any knowledge would be appreciated.. Thanks very much

The speed sensor is on top of the trans, directly below where the throttle body sits