The default setting for Github is case insensitive. Therefore, even if we change the filename locally and push, it will not change anything.

If we accidentally push small letter filename on Github and want to change it, what should we do?

First. Disable case ignore by the command below.

git config core.ignorecase false

Secondly, if you still see the original small letter files, use the command below.

git rm -r --cached .
git add --all .
git commit -a -m "remove files"
git push origin master

Then you can see the files removed.