Nissan Repair: changing serpentine belts, nissan sentra, center bolt

Question
For 2001 Nissan Sentra, 1.8 engine. How do you get the serpentine belts loose?

Answer
Loosen the center bolt of the idler tensioner pulley and then loosen the long bolt that tightens the belt.  Remove the belt when the pulley is loose enough and replace the belt.  Tighten the long bolt until the belt is tight and then tighten the center bolt.  Oh, buy a Nissan belt.