How do you replace the fan belt on a 1997 infinity Q45?

To replace the fan belt on a 1997 Infiniti Q45, first, ensure the engine is off and cool. Locate the serpentine belt tensioner, then use a wrench to relieve tension on the belt and slide the old belt off the pulleys. Install the new belt by routing it according to the belt diagram typically found on a sticker under the hood, ensuring it sits properly on all pulleys. Finally, reapply tension with the tensioner and double-check the alignment before starting the engine.