I know how to install Docker, so don't be too quick to paste in the URL.
What I need to know is how to fully undo what I did if I have trouble with it.
Specifically, I'm on a "pet" CentOS7.4 VM with Docker version 1.12.6 installed. I'm making no progress with a "docker login" problem I'm having . As I can't think of anything else to try, I wanted to try upgrading from version 1.12.6 to the latest community edition. However, I want to be sure this doesn't cause other problems, as I have to use Docker for other purposes on this VM, and that is working perfectly fine.
So, what I want to be clear on are the steps I'd have to take after following the steps described in the referenced Docker CE installation page, to revert those changes and get back to the 1.12.6 version. I imagine the core of this will be removing the repositories added in these instructions, but I want to be sure how to do this properly.