Hi everyone!

Long time since my last login here. Last time was about a Nokia N8.

Now, I would like to unbrand my Sony Xperia M4 Aqua E2306. It currently has a firmware from Videotron. I would like to put a generic firmware on it (North America). I will unlock the SIM later (I won't pay to unlock the SIM if I am stuck with Videotron firmware).

I don't know where to start. Where to DL the firmware. What it all the fuss about unlocking the bootloader (it can't on my for what I saw on the service menu), etc.

Anyone can help me?