How do you fit a fan belt on a 1.8 vectra petrol?

To fit a fan belt on a 1.8 Vectra petrol, first, ensure the engine is off and cool. Locate the tensioner pulley and use a suitable tool to relieve tension on the belt, allowing you to remove the old belt. Route the new belt around the pulleys according to the belt routing diagram, ensuring it sits securely in the grooves. Finally, release the tensioner to apply tension to the new belt, and double-check that it is properly aligned before starting the engine.