How do you change the vehicle speed sensor?

are you refering to the on in the rear diff?unbolt the little steel bracket remove the diff vent.now it it unbolted.carefully pry up a little spray some penetrating oil on it there is an oring that seals the sensor in.that also makes it tough to remove.twist and pry it up.if it breaks screw down into the sensor and keep pulling.if it wont come out time to service the diff.remove the cover and pop the sensor up.becareful not to bend any teeth on the tone wheel.reseal the cover refill the diff and replace the sensor.your speedo should work again.