The alt. belt is the easiest to adjust. There is a pivot bolt on the bottom but you probably won't have to loosen it. Just loosen the top bolt (13mm I think) where the 10mm adjuster screw is. After you loosen it just tighten the 10mm screw a few turns and then tighten the top bolt back up. Note: when the top bolt is tightened back up, the belt will get even tighter because the angle will change as the bolt is tightened so leave it slightly loose and recheck after everything is tightened back up. The whole process will take only 5 minutes. The others are a little harder because of the inaccessibility to the mounting bolts.

Also, sometimes the rubber bushings (where the mounting bolts are) will get worn and cause the alt, or any of the accesories, to sag and this will cause the belt to squeal because the belt is being pushed against the back side of the pulley. The only thing to do is replace all of the bushings and the belts.

Good luck.

Well, first make sure it is not the harmonic balancer slipping and howling. That is the main pulley on the lower front of the engine and if it is slipping it will get dangerously hot after running the engine for a short time. After that, look carefully for the adjustment arms on the alternator and AC and power steering. There is a 13 mm lock bolt that must be loosened (two on the AC and the rear one is impossible) before the 10 mm nut is used to adjust tension. If this is too difficult, someone needs to show you how to do it.