Updated: 15 December 2013 - v3
Step 1Download the skin and extract the file (using either 7-Zip for Windows or The Unarchiver for Mac).
Step 2Move the extracted folder "black code skin" into your skins folder:
Win Vista/7/8: C:\Users\<username>\Documents\Sports Interactive\Football Manager 2014\skins
Win XP: C:\Documents and Settings\<username>\My Documents\Sports Interactive\Football Manager 2014\skins
Mac OS X: /Users/<username>/Documents/Sports Interactive/Football Manager 2014/skins
Create the folder "skins" if it doesn't exist.
Step 3Start the game and go to Preferences screen and Interface tab.
You should see "Black Code SKin" as option in the skin drop down of the Overview box.
Hit the Confirm button.
Please note this skin is provided as is. It has nothing to do with Sports Interactive or SEGA and won't be supported by them.