How do you alter an object's historical content in a git repository?

Question

I have a local git repository that I eventually plan on publishing as open source. I recently noticed that one of the files has a password in it. Obviously, I need to strike that password from the entire history before I publish the repository.

A: Is there a way to access and modify the history for all revisions to that particular file?

B: I guess one alternative is to simply publish a clean version of the HEAD.

Answer 1

git rm <file>
git-filter-branch --index-filter 'git update-index --remove <file>' master

This should remove the file from all revisions.

Source: http://help.github.com/removing-sensitive-data/

Though if you are really worried, just upload a new, clean repo without the file.