How do I rename a git remote?

I currently have a git remote called heroku and I'd like to rename it to production.

$ git remote -v
heroku	https://git.heroku.com/example.git (fetch)
heroku	https://git.heroku.com/example.git (push)

$ git remote rename <old-name> <new-name>

So, for this example:

$ git remote rename heroku production

Useful docs here: https://help.github.com/articles/renaming-a-remote/

Be aware that until Git 2.11, git remote rename might try to rename a non-existing remote!

That is fixed in Git 2.12 (Q1 2017): See commit e459b07, commit af5bacf (19 Jan 2017) by Johannes Schindelin (dscho).
^{(Merged by Junio C Hamano -- gitster -- in commit fe575f0, 31 Jan 2017)}

> ## remote rename: more carefully determine whether a remote is configured

> With anticipatory tweaking for remotes defined in ~/.gitconfig (e.g. "remote.origin.prune" set to true, even though there may or may not actually be "origin" remote defined in a particular Git repository), "git remote rename" and other commands misinterpreted and behaved as if such a non-existing remote actually existed.

---

With Git 2.26 (Q1 2020), "git remote rename X Y" needs to adjust configuration variables (e.g. branch.<name>.remote) whose value used to be X to Y.
branch.<name>.pushRemote is now also updated.

See commit b3fd6cb (01 Feb 2020), and commit f2a2327, commit 923d4a5, commit ceff1a1, commit 1a83068, commit 88f8576 (27 Jan 2020) by Bert Wesarg (bertwesarg).
^{(Merged by Junio C Hamano -- gitster -- in commit d0038f4, 25 Feb 2020)}

> ## remote rename/remove: handle branch..pushRemote config values
> ^{Signed-off-by: Bert Wesarg}

> When renaming or removing a remote with

> git remote rename X Y git remote remove X

> Git already renames/removes any config values from

> branch..remote = X

> to

> branch..remote = Y

> As branch..pushRemote also names a remote, it now also renames or removes these config values from

> branch..pushRemote = X

> to

> branch..pushRemote = Y

And:

> ## remote rename/remove: gently handle remote.pushDefault config
> ^{Signed-off-by: Bert Wesarg}

> When renaming a remote with

> git remote rename X Y git remote remove X

> Git already renames or removes any branch.<name>.remote and branch.<name>.pushRemote configurations if their value is X.

> However remote.pushDefault needs a more gentle approach, as this may be set in a non-repo configuration file.
In such a case only a warning is printed, such as:

> warning: The global configuration remote.pushDefault in: > $HOME/.gitconfig:35 > now names the non-existent remote origin

> It is changed to remote.pushDefault = Y or removed when set in a repo configuration though.

As you linked and said yourself in your answer, you just have to type

git remote rename heroku production

see bottom of the page: https://git-scm.com/book/en/v2/Git-Basics-Working-with-Remotes