Insert your grinding blade into your metal grinder according to the instructions for your particular grinder. The grinding blade operates in a similar fashion as the skill saw.
Put your safety goggles on and power on your grinder.
Spray aluminum lubricant over the area you intend to grind, coating the area evenly.
Feed the area you intend to grind into the blade and use smooth, even motions to work the area of the aluminum. Keep the aluminum moving as letting sit idle on the grinding blade can cause it to become uneven.
Repeat the steps until you have reached the desired shape of your aluminum.