title: Git - rollback to a previous commit
body: <p>I committed my work (note <em>not</em> pushed) in a known good state. I have since made unwanted local changes (without committing or pushing them). What is the command to undo these changes and revert to my previous commit state?</p>
  
  <p>Please accept my apologies for the beginner question but the suggestions turned up by my googling seem arcane and I would like to be confident in my actions.</p>