How do you change a tension belt in a Opel Astra 200 i e?

To change the tension belt in an Opel Astra 200i, first, ensure the engine is off and cool. Locate the tensioner pulley and use a wrench to relieve tension on the belt, then remove the old belt from the pulleys. Install the new belt according to the routing diagram, ensuring it is properly seated on all pulleys. Finally, release the tensioner to apply tension to the new belt and double-check its alignment before starting the engine.