# <f> = SHA Code "ex. ea69188941"

git checkout --orphan temp <f>      # checkout to the status of the git repo at commit f; creating a branch named "temp"
git commit -m "new root commit"     # create a new commit that is to be the new root commit
git rebase --onto temp <f> master   # now rebase the part of history from <f> to master onthe temp branch
git branch -D temp                  # we don't need the temp branch anymore

git push -f

# The following 2 commands are optional - they keep your git repo in good shape.
git prune --progress                 # delete all the objects w/o references
git gc --aggressive                  # aggressively collect garbage; may take a lot of time on large repos