1. ​Perform a search on Bugzilla to find the bugs you're interested in (or a superset thereof).
2. Click the "Change Several Bugs at Once" link at the bottom of the search results page.
3. Check the checkbox next to each bug you want to change.
4. Make your changes in the form near the bottom of the page.
   1. For example, to CC yourself on a bug, type your Bugzilla username into the "CC List:" field and ensure that the popup to the right says "Add these to the CC List".
5. Click the "Commit" button.