CSS Background change?

[tyleto]

Okay, so as from what I've seen there is only ONE tutorial out there that goes over how to change the background image for the CSS.
HOWEVER, I don't know if it's just me but the tutorial is very hard to understand, mainly because of unclear directions and problems in English. Can somebody please run me through the process?

[Cless]

I just download the pack of super master hand but what language do you speak?

[tyleto]

Just English, but I know how to replace it now so no need to worry. Now I just need help getting a program or something that can rearrange the CSS portraits,