Where to buy - Mi2 phone


i have a question , how can i change the xiaomi english version i buy in china to other language ? such as Russian / French / Spanish etc ? I am stupid at the software and engineer , even i can easy get xiaomi , but I do not know how to change the language for buyer , i am so sorry , pls help me . pls help me explain , where to find the Rom , and how to flash the rom ?It would be very helpful , thanks in advance ! Thank you