# 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^