How do you fix an accelerator cable on a 1996 Nissan Sentra?

My son's '97 Nissan Sentra did not have a cable but a VSS(vehicle speed sensor). His odometer and spedometer did not work at all. We replaced the VSS and it now works. We bought the VSS for about $20 from car-stuff.com and my son and his friend put it in in about a 1/2 hour once they figured out where it was located. You will have to get under the car to do that.