I thought I was going to have to sell my CW40 because I simply couldn't power the spring and rod into position. After several tries I almost gave up when I saw a 1/4" dowel rod in my kit. Inserted it through the hole in the slide and into the spring up to where the rod was. That prevented the spring from contorting during installation and popping into space. MY problem was weak hands and flexing spring. The dowel rod made all the difference in the world and I can now easily reinstall the spring/guide rod so...CW40 stays. Maybe this will help someone else.