title: How do you un-deploy Cloud Functions for Firebase?
body: <p>I was experimenting with Cloud Functions for Firebase and deployed one of the samples in the <a href="https://github.com/firebase/functions-samples/" rel="noreferrer">functions-samples repo</a> and linked it to an existing project using <code>firebase use --add</code>. </p>
  
  <p>Since I was just playing around, these files were not added to my version control, and I no longer have access to the machine this was done on. I would like to build on this function or create new ones, but I am unsure how to either 1) modify and re-deploy over the original function or 2) un-<code>use --add</code> and start fresh. I see the function in my firebase console but no 'delete' or 'remove' button and have read through the CLI docs looking for clues to no avail.</p>
  
  <p>Thanks for adding functions to the firebase 'stack.' Any guidance is much appreciated.</p>