I picked up an ARF Nobler from a member of the R/C club I talked my way into a few years ago. He hadn't flown it yet and in a real somber tone, told me to "take the wing off and check the controls". Glad I did! Yikes! Wish I could post the before-and-after pics from my phone here, but no matter, it's good now. Anyhow...
To replace the leadouts, I cut two short lengths of 1/16 brass tubing, maybe an inch long. I cut off the ends of the leadouts and slipped the tubing halfway on and squeezed it with pliers. I them slipped the ends of a 20 foot length of leadout cable into the other half of the tubing and squeezed it as well. I then took the bellcrank off its post (there was no nut holding it on!) and slowly pulled the old leadouts through the wing, drawing the new leadout wire through with them. I then cut off the old leadouts and attached the new wire to the bellcrank, using brass tubing to reduce wear, as is commonly done in an installation intended for long term use. After the bellcrank was reinstalled on its post, I cut the leadout wire 6 or 8 inches from the wing and made the ends.
Hope this works for you.
Bob in NEPA