how to delete history of a file in git code example

Example 1: remove file history from git

git filter-branch --index-filter "git rm -rf --cached --ignore-unmatch path_to_file" HEAD

Example 2: how to remove one file from git history

To replace all text listed in passwords.txt wherever it can be found in your repository's history, run:
bfg --delete-files YOUR-FILE-WITH-SENSITIVE-DATA