This snazzy little bat (or two) file will either move all the extras to your desktop or delete them (Not recommended). This is particularly useful if your W3 is on a small HDD and your desktop or wherever you want to put it is on a larger one.

Some assembly required (Installation) (If you're good with .bats you can probably figure out what this consists of):

• Extract the rar with an unzipping program.
• Right click on which ever bat you're using and hit edit.
• Hit Ctrl + H
• In Find What, type "[WITCHER 3 DIRECTORY]" (without quotes)
• In Replace With, put your Witcher 3 Folder (WOW!) By default it's C:\Program Files\Steam\steamapps\common\The Witcher 3 but you may have changed it.
• Hit Replace All.
• Now type "[NAME]" in Find What.
• And your User name in Replace With.
• Hit Replace All.
• Close it and save it.
• Run it!
  

If you (and I) did everything right, you should see the folders on your desktop and still in your W3 folder. Don't panic! These are symbolic links, basically glorified shortcuts. These take up no space and exist because, when Steam updates your game or when you verify cache, it'll redownload all 5GB of extras again. This is why I don't recommend just deleting them.

Now put the folders anywhere!

Tell me if it doesn't work. Make sure it wasn't you not editing the file properly.

Enjoy!