Overriding An Asset
You can override images and other assets in AVCMS without overwriting the original file. Lets use an example image.
Say you see an image and you see it's URL looks like this:
You can take a copy of that file and place it in this matching directory, but in the webmaster folder rather than the web folder:
After making your changes, enter your admin panel and from the cog icon in the top-left corner, select Regenerate Assets and your image should now show in place of the old one.