So far I've rewired the columns on my '69 Shelby with the tilt/pop wheel, '65 F100 with just a horn and turn signals, a Camaro or two, and the '57 Chevy. Our local parts store (NAPA) has the replacement harnesses, even for something as weird as the Shelby. They come with the replacement turn signal switch, the follower for the horn, and other wires as needed. Everything I've done so far is old enough that they didn't have the ignition key in the column, but I've got that '79 Trans Am to do soon enough.

All the kits have reused the connector, but the wiring was simple enough. The first one, I took some duct tape and attached an old speedo cable core to the ends of the wires. Applied a little electrician's wire pulling lube (skipped that after the first one - didn't like the slime), and fed the cable down the column. Just pulled it through and then reattached the connector.

You'll need the pin tool for your connector, and it sounds like you need the connector. That will probably be a wrecking yard item. If Painless uses anything other than the stock connector, you'll need theirs, but it sounds like they do the same thing - want you to save your old connector.

I've done the main wiring harness and underhood for the Shelby, and the same process applied to the bulkhead connector. Biggest challenges are that I'm a little color blind (had my daughter check my knitting to make sure I got the right ones where illustrated), and the sheet that was supplied with the harness for the F100 wasn't accurate. Good think I took a photo of the connector on the harness before I pulled it apart.

The connectors have the pins/sockets on the wires. You just have to remove the old ones, using a tool that presses the locking clip on the old one. Then feed the new pin or socket into the connector block until it snaps down. Shouldn't have to cut anything to remove or reinstall.

Good luck with it.