Does anyone know the way how to tighten the AC/ PS belt on a Mazda protege 2000 1.6l

[mazpro00]

When ever i turn my ac or rear defroster with a cold engine the belt squeals when i start to drive from a cold engine and will last for 20 seconds and it will not squeal again until i drive the car with the engine cold and the ac is on. This has been happening for 2 years since i got that belt replaced never made that noise before replacement. I just now wanted to do something about it