title: Removing files from past commits in GitHub repository with BFG Repo-Cleaner
body: <p>I have a file in my GitHub repository that I would like to remove from my previous commits. I used BFG Repo-Cleaner's <code>delete-files</code> command and it appeared to work, but when I go on my GitHub repository the file is still on all the previous commits. If I try and do the command again, it gives me a </p>
  
  <blockquote>
    <p>BFG aborting: No refs to update - no dirty commits found??</p>
  </blockquote>
  
  <p>Am I misunderstanding how BFG works? If so how can I remove the file from my past commits on GitHub?</p>
  
  <p>Here are the steps I took: </p>
  
  <ol>
  <li>Cloned a copy of my GitHub repo into a local folder using the <code>--mirror</code> flag.</li>
  <li>I then <code>cd</code> to my local visual studio project. </li>
  <li>I then entered in the command <code>java -jar bfg-1.12.1.13.jar --delete-files &lt;.json file I wanted to delete&gt; &lt;my local clone copy from step 1&gt;.git</code></li>
  <li>I then entered in <code>git reflog expire --expire=now --all &amp;&amp; git gc --prune=now --aggressive</code></li>
  <li>Ran <code>git push</code></li>
  </ol>