How do you replace speedometer cable in a 1983 gmc vandura?

To replace the speedometer cable in a 1983 GMC Vandura, first, disconnect the negative battery terminal for safety. Remove the speedometer head from the dashboard by unscrewing it and gently pulling it out. Next, locate the speedometer cable at the transmission, disconnect it, and remove the old cable from the housing. Install the new cable by reversing the process: attach it to the transmission, feed it through the housing, and reconnect it to the speedometer head before securing everything back in place.