More information about this fix for centerboard leak

I have read the following fix for the centerboard uphaul/downhaul leak with the wire cutting thru the centerboard trunk.
Used a 3/4" metal pipe that I cut lengthwise into with a hacksaw to make a "hole threader". I then went to the hardware and bought a 1" long ABS plastic threated nipple with a nut fitting on the other end. (about $2) and capped that with a 1/2" end cap with a 1/8" inch hole in the end for the wire. I think it is used to couple a threaded pipe to a slip fit pipe. It stops all water from coming in to the cuddy. A simple threaded nipple would likely do the job also. About an inch long. The gap between the two fg hulls is only about 3/8" at the most, the thickness of each hull is 1/4" at most, so a total nipple length of 1" is really all you need. I liked the nut idea because it allow me to use a wrench to install it. Too simple!
I would like to do this repair but have a few questions about the above procedure. If anyone has done this repair I would appreciate a reply.
Question 1. How to remove the plastic o-ring that if on the forward end of the centerboard trunk that has the cable running thru it? (preferably not breaking it)
Question 2. What do you do with the 3/4 metal pipe hole threader listed as the first part of the fix? What am I trying to thread - the part where the plastic o-ring is currently inserted or the centerboard trunk where the fiberglass hull encases the centerboard?
Question 3. Once "threaded" do I leave the metal pipe in place or remove it to insert the 1" long abs plastic with a nut on the other end?
Thanks,
Bob