well i can tell u this much, i was gonna replace it on my 65, it wasnt broken, just sloppy. i decided not too because it looked like the wires were connected all the way down the steering column and it would have been a big job fishing the wires up through it. basically like either a cut and splice thing or re run all the wires. someone correct me if im wrong please, and make me happy
I bought the kit from cal-mustang for replacing it on my 66. It was simple enough you just thread the new wires down through the steering column (not too hard cause theres a slot that they go through). Then you have to read the directions for what color goes with what original wire. Took me about an hour to do.
You guys may know this trick, but I'll post to up my post count
What you do is pull the old cam up where you can get to the wires connected to it with a little extra room.
One wire at a time do the folllowing:
1) cut it off the old cam as close as possible so you have enough for step 2.
2) overlap the end of the new wire with the cut top of the old wire about 2 inches.
3) Use electrical tape and wrap from 1 inch below overlap to 1 inch above overlap so the old wire is now attached to the new wire. Try not to make it any bulkier than necessary.
4) Pull the old wire down thru the steering column (toward the floorboard) pulling the new wire with it until you can reach the new wire at the bottom.
5) remove old wire from plastic plug, and insert new wire into plug.
Thats it. I've done a bunch this way and it is pretty quick and works well.
Occasionally the fit is tight enough that the old wire pulls loose from the new wire half way down the steering column.
Don't stress.. you have lots more wires going down, just pull the wire back out and piggy-back it with one of the others.
Worst case the LAST one going down pulls loose, then just reverse the operation to pull an old wire back up and piggy-back the two back down on it.
Is it the cam you want to replace, or the switch? If it's the switch then Credzba has got it just right, if it's the cam, then just slide the old one off the shaft, and slide the new one on. You have to make sure it all lines up when you put the steering wheel back on though.
I found it easiest to just replace the whole steering column harness back to the plug under the dash. Didn't take too long and with 40 year old wiring, I felt it safest to go ahead and replace as much as possible rather than having the splice.