Wheatley look-a-like Personality Cores By Slade Skox
additional skinning done by dum6azz aka D3M0L1$H3R
I mainly made this for the Portal 2 Collab but decided to release it to the general public as well.
It's not an exact replica, nor is it the highest quality, but I'm satisfied with it.
Extract the two folders in the rar file to:
So for example C:\Valve\steamapps\marcomw\portal\portal
That's really all you need to do.