Reverting to a previous version
Our system automatically stores past versions of a document.
As you make changes to a file, and save them, a 'revert' drop down will appear next to the 'close' button.
You can click a previous version and it will automatically restore the file to how it was on that day and time.
If you intend to make a lot of changes though we'd advise you take a backup of your theme first, as the revision history will only go back so far.