They are both very simple. For the ps belt, loosen the nut on the front of the belt pulley. It's either a 17 or 19mm nut. Then loosen the 12mm bolt behind the pulley that runs parallel to the pulley. That will allow the pulley to slide towards the engine and give the belt some slack. For the alt belt the tension comes straight from the alternator. Loosen the 12mm nut on the top side of the alternator then loosen the 14mm bolt and nut on the bottom of the alternator. The alternator will pivot on the bottom bolt and pivot towards the engine allowing slack in the belt.
For reinstall, use a pry bar on the back side of the alternator once the belt is back on. Pry the alternator away from the engine till the belt tension is sufficient and at the same time tighten the 12mm bolt on the top of the alternator. Once that is tight then tighten the lower nut and bolt. For the ps belt, tighten the 12mm bolt behind the pulley and that will pull the pulley away from the engine and apply tension to the belt. Once you have proper tension then tighten the nut on the front of the pulley.