ModifyGitHistory.sh

# Remove e.g. large files
git filter-branch prune-empty -index-filter "git rm -cached -f -ignore-unmatch TWUndDieWeihnachtsmaenner.mpg" -all

# Edit commit message of the last commit
git commit --amend

# Modify last or one of the last 3 commits or only their commit messages
git rebase -i HEAD~3

# Merge current staging area content with last commit
git commit --amend

# Remove last commit (changes are kept in local working area)
git reset --soft HEAD^

# Remove a single or multiple tags (first git command is local removal, the second remote)
TAG='v0.1.0'; git tag -d $TAG && git push origin :$TAG
for TAG in v0.2.0 v0.2.1; do git tag -d $TAG && git push origin :$TAG; done

See also https://demisx.github.io/git/2014/11/02/git-prune-local-tags-dont-exist-remote.html