One: Unplug the saw. Then remove the blade and blade guard. Then re-install the blade without the guard. Place a 24" framing square LIGHTLY against the blade as shown in picture below. The blade flexes easily.
The adjustment is made by loosening the two large bolts and turning the allen screw in or out. Adjust the screw then tighten the bolts. Repeat several times until it's square. Sometimes when you tighten the large bolts, the adjustment changes. The allen screw is metric.
Randy