correct-name-in-git.sh

#!/bin/bash

# https://help.github.com/articles/changing-author-info/

export NEW_NAME="your correct name here"
export NEW_EMAIL="newemail@example.com"

for EMAIL in {oldemail1@example.com,oldemail2@example.com,oldemail3@example.com}; do

git filter-branch -f --env-filter '
OLD_EMAIL="'$EMAIL'"
CORRECT_NAME="'$NEW_NAME'"
CORRECT_EMAIL="'$NEW_EMAIL"
if [ "$GIT_COMMITTER_EMAIL" = "$OLD_EMAIL" ]
then
    export GIT_COMMITTER_NAME="$CORRECT_NAME"
    export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
fi
if [ "$GIT_AUTHOR_EMAIL" = "$OLD_EMAIL" ]
then
    export GIT_AUTHOR_NAME="$CORRECT_NAME"
    export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
fi
' --tag-name-filter cat -- --branches --tags

done

# Verify everything with `git log` and,
# if it's correct run:
# git push --force --tags origin 'refs/heads/*'