Mine was on real tight. You can use a box end wrench and brace it against one of the other bolts and use that to stop the pulley...but that didn't work for me. I had to go to autozone and rent the fan clutch removal tool. It's just a large box end that fits around the 4 pulley bolts. Then you use that with your large adjustable wrench to crank the clutch off. (my autozone only had ford kits, so I had to use the crescent wrench and the kit wrench....if you find a GM kit, you'll have the right sizes in the kit)