I don't know if I have to get root access. My phone is virgin
Is there any guide?
No need for root.
You have to unlock your bootloader. As I know, not every phone is eligible for that.
Then you have to install custom recovery on your phone (CWM for instance)
Now you can install mods. Just put .zip on sdcard and flash it via custom recovery (in CWM - install zip from sdcard)
Guides : http://forum.xda-developers.com/show....php?t=2558638
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?