How do you change the alternator belt on a 1991 vw polo?

To change the alternator belt on a 1991 VW Polo, first, disconnect the battery to ensure safety. Loosen the tensioner bolt and adjust the tensioner to relieve tension on the belt. Remove the old belt and replace it with a new one, ensuring it is properly aligned with the pulleys. Finally, re-tension the belt, tighten the tensioner bolt, and reconnect the battery.