Help for theming stock 4.2.1?

Hello everybody, I want to theme a little bit my stock nexus, change the system background, default wallpaper and so many more things.



Any themer can help me with 4.2.1 because I I've seen that has changed than 4.1.1.



Excuse me for my English, I'm from Spain.



Cheers!

by alexpitonzodj via xda-developers