That's what google is good for: https://www.google.com/search?q=android+root
But - before you start - read a sad story here: http://forums.cnet.com/7723-32456_102-600863/hardware-keys-aren-t-responding/?messageId=5494936#message5494936
If you don't want to experience these kind of things, stay far from rooting.
I am using xperia ray which is now at android 4.2 condition.
Can i root this phone to customize it. And also want to kow how to do root. I heard from people around me that they had root their phones, but none sharing how they actually done it. I would like to know from which site i will get to know more details about root. Help will be appreciated.