How to unlock my W300i, help me please.

I have a sony w300i, it is locked to the Mexican mobile carrier TELCEL. I want to unlock it to use it with another company sim card and I am new at this. Can anyone help me and explain to me step by step how can I unlock it?

Thank you for all your help.

use simox unlock patch, search the forum for simox patch. Installing may help use your phone with other service providers. Good luck , Please read tutorials of simox before applying patch! Good day.