How do i fit Alternator belt Astra 2002 1.7 diesel?

To fit the alternator belt on a 2002 Astra 1.7 diesel, first ensure the engine is off and cool. Locate the tensioner pulley and use a suitable tool to relieve tension on the belt. Remove the old belt and route the new belt around the pulleys according to the belt diagram, which can usually be found in the engine bay or in the owner's manual. Finally, release the tensioner to secure the belt in place and check for proper alignment before starting the engine.