Once the stock is removed you can put a wrench on the hex nut, BE CAREFUL, The tube is made out of aluminum the nut or the whole tube may turn. The problem is, if you want to get the spring out you have to turn the nut while the tube remains stationary. And you should clean it its not as sealed as you think. My benelli started to act up and I cleaned the tube and it was a new gun. Now for some Truth The first time I did this I Crushed the tube using a small pair of vise grips. That's why BE CAREFUL, I learned my lesson to be patient.Now I can take it apart in my sleep. But it cost me.