How to unroot,newbie here.

[Yufan]

Hello people of Phandroid, I'm Yufan and recently I bought the phone Android HTC Sensation XE (Z715e) and it was bought on a Chinese website (Taobao,something like Amazon) and I'm very new to Android. I believe it is rooted as it has a custom Android Market that is full of Chinese stuff even though I set the language of the phone to English, it also came with a few apps pre-installed. So I was thinking if I can get a normal Market and get the normal Android system that people NORMALLY get when bought. Noob here so if you are going to help me with some technical stuff then please keep it simple. Thank you Please feel free to ask information about the phone if necessary. Thanks again

Here are some information:
Mobile network type:HSDPA, IMEI SV:01, Android Version:2.3.4, HTC Sense version:3.0, Software Number: 1.0.0.Z715e, Browser Version:Webkit/533.1