I took a scrap piece of 4-40 rod and made a curved hook at one end. I then attached the spring to one wing. Take your 4-40 rod and put through the hole in fuse from opposite side and hook the free end of the spring. As you pull wing tight against fuse, also pull the 4-40 rod to pull spring through other side. Then attach the other wing and your all set. Works like a charm.