Well, I suppose sometimes it looks easy just because it is. I finished this up a little while ago with success, and it is just that easy.
The only problem I had was that I thought I’d be “smart” and replace the clips (partly given EdB’s note about their ease of loss). So I bought a pack from NAPA (specifically reading transmission line clips). Well they were close but not close enough. Unfortunately, as I was having a hard time I just assumed it was me not knowing what I was doing. They didn’t get on the fitting easily; had to pry them back out a bit to get the new line to snap in; couldn’t get the dust cap back on. Luckily I hadn’t lost or damaged any of the OEM clips and none were corroded or anything. So I just tried one of those after the first NAPA clip and it was a piece of cake. I’ll whine at the NAPA parts guy when I take the other ones back.
So if anyone comes across this later looking for advice - do have new clips on hand. They are easy to lose. But get them from GM.
Thanks to all for the input.