Just download the game and install it in a other location, copy the dds folder from your new install, delete the older one (yes, delete it to remove any unused dds files added by some mods), and paste the new in place.
If you are like artist, developing new dds, you may even consider creating local git repository over your copy of game, and keep versioning files when you are happy about particular version, so you later can go through the history of changes, or revert in case something breaks. Also you will be able to detect all changes made by next official patch.