To install just put the tf folder in your team fortress 2 folder, which can be found at
C:\Program Files (x86)\Steam\steamapps\<YOUR STEAM ID>\team fortress 2\tf
or
C:\Program Files\Steam\steamapps\<YOUR STEAM ID>\team fortress 2\tf

Feel free to modify this skin as you like, as long as you give credit.

-Dinnerjoe