1. You can open command prompt.
2. Create a fresh, bare clone of your repository:
    git clone --bare https://github.com/user/repro.git 
    cd repro.git

3. If you use the official website's bash you will get error:

WARNING: Ref 'refs/heads/master' isunchanged。

So just copy the follow script and save as changename.sh:

git filter-branch --commit-filter '
    case "$GIT_AUTHOR_NAME" in
      *[Jj]ersey*[Ss]u*)
          GIT_COMMITTER_NAME="Jersey Su"
          GIT_COMMITTER_EMAIL="loverjersey@gmail.com"
          GIT_AUTHOR_NAME="Jersey Su"
          GIT_AUTHOR_EMAIL="loverjersey@gmail.com"
          git commit-tree "$@"
          ;;
      *)
          git commit-tree "$@"
          ;;
      esac
' HEAD

4. And execute:

C:\Program Files\Git\bin\sh.exe "X:\changename.sh"

5. git push --force --tags origin master

6. rm -rf ./repro.git 



[Reference]
https://help.github.com/articles/changing-author-info/
http://codex.wiki/question/1572846-5253