Change my caption buttons.

[masaladosas]

I want to edit my caption buttons and replace the X (close button) with an image. Which file do I need to edit?

[Mr GRiM]

I want to edit my caption buttons and replace the X (close button) with an image. Which file do I need to edit?
Windows and Caption Buttons > Aero > Dwm Window > CloseButton > Normal Glyph > 96dpi