Using Windows explorer, navigate to your Steam Folder, which is by default "C:\Program Files (x86)\Steam\steamapps\common"
Right Click on the "7 Days To Die" folder, and select Delete
Confirm that you want to delete the "7 Days To Die" folder
In Steam, right click on the "7 Days to Die", and click on Properties
Click on the "Local Files" tab
And click on "VERIFY INTEGRITY OF GAME FILES"
This will download a fresh install of 7 Days to Die of the latest stable release.
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