Delete a file, and destroy its history in git.

git-destroy.sh

#!/bin/bash

# This script removes a file from the git repository and destroys all its history.
#
# Based on https://help.github.com/articles/remove-sensitive-data/
#
# To do a dry run, add a -n to the git rm command. I.e.
#       "git rm -n --cached --ignore-unmatch $1" 

printf "Really destroy $1 ? y/[n] "
read -n 1 destroy

if [ "$destroy" == "y" ]; then
    printf "\nDestroying $1\n"
    git filter-branch --force --index-filter \
        "git rm -r --cached --ignore-unmatch $1" \
        --prune-empty --tag-name-filter cat -- --all
else
    printf "\nDid not destroy $1\n"
fi