I had exactly the same problem with my Elu Type 4 router when I could not get the spring guide tubes and springs back in after removal. I found the brass tube tilting to one side made it impossible to replace the spring and spring guide tube.
Eventually I used a large lag-screw (or coach screw) to screw tightly into the brass tube, which I then pulled out with the brass tube. It took quite a lot of force to pull it out. But that was the answer to my problems. After regreasing and cleaning, the springs and spring guide tubes went back perfectly.