Help with changing player frame / Target Frame

[ztealmax]

Hello is it any easy way to change the texture of player/target frame?

Can i just use this and add my texture at that location:
x:\World of warcraft\interface\CharacterFrame\UI-Player-Portrait.blp
the new texture?

Or do i need to call it from an lua script?

If i need to make small addon/lua script
how do i call it the easiest way?

Guess i could use something like this addon
http://www.wowinterface.com/download...rFrameArt.html
however when trying to use my own skin it mirrors the image
Anyone got a clue about why?
Sincerally
Ztealmax "Martin"