The following worked to update author/email, etc. However, it left a detached commit(the red in the image) that is the original initial commit. How can I get rid of it?
git filter-branch --commit-filter \
'\
export GIT_AUTHOR_NAME=userid;\
export GIT_AUTHOR_EMAIL=useremail;\
export GIT_COMMITTER_NAME=userid;\
export GIT_COMMITTER_EMAIL=useremail;\
git commit-tree "$@"'