Change "modern" look to a good old look

How can I change the new “modern” look of my updated eM Client page? I up-dated my eMail Client too quickly, thinking I could change the “skin” later. But I don’t see that option. Thanks. (Version 5.0.17263.0)

I think what you’re looking for is in:
Tools menu -> Settings -> Appearance -> Themes

Thanks! That was where to find it.