if it is a Windows 7 OS, you can download the English language Win 7 ISO then install that, activate it using the serial no. provided to you on the laptop. Make sure to create a set of product recovery media from Drive Q (Lenovo_Recovery) before you do this.
This is the only way to do it, as Lenovo can't provide a different language installation media. (in the old day the recovery media Lenovo ships have every language, but that no longer seems to be the case).