How to rename a git commit

It's important to note that if you have already pushed to origin this will create a lot of problems for other users of the repo.

To change the message of the last commit (if you haven't pushed to origin):

git commit --amend -m "the new message here"

To change the message of multiple commits or a particular previous commit (again if you haven't pushed to origin):

// use this and follow the steps, replace n with the number of commits you want to change/consider 
git rebase -i HEAD~n

References:

https://stackoverflow.com/questions/179123/how-to-modify-existing-unpushed-commit-messages