Change the author of a Git commit using filter-branch, modified from GitHub's git-author-rewrite.sh

git-change-author.sh

#!/bin/sh

git filter-branch --env-filter '

TARGET_COMMIT="b2e9c940f383c916d783d414ea8626c59922661a"
CORRECT_NAME="John Doe"
CORRECT_EMAIL="john.doe@gmail.com"

if [ "$GIT_COMMIT" = "$TARGET_COMMIT" ]
then
    export GIT_COMMITTER_NAME="$CORRECT_NAME"
    export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
	export GIT_AUTHOR_NAME="$CORRECT_NAME"
    export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
fi

' --tag-name-filter cat -- --branches --tags