I just bought new fork tubes to replace the bent one's on my Tomos A3 rebuild. The new tubes came with fresh springs but not the Spring Plug Nuts. I'm attempting to scavenge the Plug Nuts off the old tube springs... It seems straightforward, but try as I might, I'm only twisting up the old spring, rather than removing the Nut. What am I doing wrong here? Is there a trick to this? A tool perhaps?