I believe the center shaft is a Torx bit (maybe Allen) and I usually can get a wrench on the nut. You have to hold the center shaft still while loosening the nut on the shaft. Wrench on nut with Torx going right through the center...loosen. A little bit of a PITA but doable. Im sure GM has a special tool or something But I havent had a problem doing it this way yet.

 

Thanks for the reply. I went out and was able to take it off right after I wrote the post. I used a pair of vice grips on the nut and a torx on a 3/8 breaker bar and was able to loosen it to take it off. Put the new one on and put the car back togeather. I started it for the first time with the new cam and pulleys. It has a bad *** lope. Thanks Jessie

 

How do you remove the stock pulley from the alternater. I have already installed the crank pulley, But all the instructions say for installing the alternator pulley is to remove stock alternator pulley. Is there a special tool required to remove this pulley.