[KeboPR]

Right now I am using stock Android MDL Root and I recently received the notification to update to de MF9 Android System. What do I have to do? Any link to any tutorial? Can I just update and that is it? What do I have to do?

[TCaRRtel]

I'm wondering the same thing. I tried to update mine but when my device starts the countdown it gets to 0, tries to reboot to install, then doesn't. I'm considering using odin to return my phone to stock, updating then rerooting.

[Droid X_46]

I had the same problem a week ago when I was trying to update my custom ROM. Do not Update through the phone when it tells you that a SYSTEM UPDATE is read to be installed. Make sure that you have ODIN 3.06 or 3.07 if possible, a fairly recent version is preferred. Click on the URL and it will explain everything [FIRMWARE][ODIN] All Sprint Firmwares {7/16/13} - xda-developers
As long as you follow the directions you will be able to update to FIRMWARE MF9 within 5-10 minutes at the most. Let me know if you have any problems or further questions. I hope I was able to help you.