Simply place the tf folder into your team fortress 2 folder and let windows do the rest.
If the folders exist just allow it to replace them. It won't do any harm what so ever.

If you ever want to delete this skin but fear of having missing textures afterwards don't worry.
The source engine will just simply read from the game cache instead.

Thanks and have fun.
- lionheart1066 (Glubbable)
http://www.steamcommunity.com/id/lionheart1066
(Why I am putting this here I don't know.)