I want to install the firmware to a new MIF . But I have not the file

Hello

I have one of your MIFI.A friend of mine installed a firmware Open WRT modified that works very well.

I want to install that firmware to a new MIFI that I just bought.

I have not the file (bin or another) to install it on the new mifi.

How can I do that? Could you help me? My friend went to another country,