git filter-branch --commit-filter '
        if [ "$GIT_COMMITTER_NAME" = "convert-repo" ] || [ "$GIT_COMMITTER_NAME" = "some_other_name" ];
        then
                GIT_COMMITTER_NAME="Some Name Here";
                GIT_AUTHOR_NAME="Some Name Here";
                GIT_COMMITTER_EMAIL="<someemail@here.com>";
                GIT_AUTHOR_EMAIL="<someemail@here.com>";
                git commit-tree "$@";
        else
                git commit-tree "$@";
        fi' HEAD;