[LG G Flex 2] tdorid44:
I am NOT responsible if you brick your phone while following the instructions given below!!

Credit goes to [MENTION=1339904]randrew87[/MENTION] and [MENTION=1004818]Alex_XV6700[/MENTION]

Findings so far for ZV9 Update:

First, the rooted .img can be found here.

Note: I was on ZV6 and followed the instructions here: http://xdaforums.com/g-flex2/general/return-to-stock-ls996-stock-img-t3217089 - to get back to UN-root for ZV6. Once I was un-rooted, I did all OTA updates to ZV9. If you enabled bands using the "Shortcut Master" app in ZV6 before unrooting, all bands enabled will stay when upgraded to ZV9.

Simply follow the same steps for previous ZV6 updates to install ZV9 root.img:

1) Download LG Flex 2 USB Driver (google, this one is easy - it's a 10.9MB LG driver)

2) Download LG_Root.zip from here: https://www.androidfilehost.com/?fid=24052804347788843

3) Go to Settings -> General -> About Phone -> Software Info -> and tap Build Number 7 times until Developer mode is enabled.

4) Unzip the zv9 rooted .img

5) Plug in the phone to computer and copy the firmware file ZV9system.img (make sure to have the "ZV9system.img" file name!!) to the root folder.

6) Unzip the LG_Root.zip

7) Power off Phone, then press and hold volume up while plugging into computer to get into "download mode". Phone screen should show "download mode" briefly.

8) From LG_Root folder run "ports" bat file. it should show you which port the phone is connected to, you are looking for the port for LGANDNETDIAG1, in my case it was COM4, it will be different for you

9) Open a command prompt (windows - run > cmd) and go into the folder that you extracted LG_Root into (cd C:\directory\to\ LG ROOT)

10) Then run the following command "Send_Command.exe \\.\COM4" - No quotes, with COM4 replaced by the port you saw from step 8. You should see something that says "SPECIAL COMMAND: ENTER, LEAVE"

11) then type "id" and press enter (no quotes), you will see something like: uid=0(root) gid=0(root) context=u:r:recovery:s0, if you don't see this repeat step 10 until you do

12) Run following dd command: "dd if=/data/media/0/ZV9system.img bs=8192 seek=58368 count=522240 of=/dev/block/mmcblk0" no quotes

around the command

13) it will take a few minutes and bring you back to the "#" prompt. type LEAVE hit enter

14) your phone will reboot and you will be rooted on ZV9!

This is where things get tricky

Note: It is still being worked out how to get 4G LTE band re-enabled on ZV9!!

The latest testing instructions are given by [MENTION=1339904]randrew87[/MENTION] here: http://xdaforums.com/showpost.php?p=64122754&postcount=385 - When getting to step 2 (2. get your MSL code HERE follow parts I & II of the tutorial.), I was not able to run "Basic Flasher" due to Windows 10 issues. I could also not get my MSL by dialing ##443336772#. I ended up having to start a Sprint LiveChat and give them my phones MEID. I made up some technical excuse on why I needed my MSL number and the chat rep bought it and provided it to me!

Now that I had my MSL code, I was able to complete the steps [MENTION=1339904]randrew87[/MENTION] provided:

However, LTE Roaming Enabled was grayed out for me. I could not figure out a way to turn it on. I am also not able to keep a consistent band for LTE when LTE DOES show up. I've attached some screenshots of the settings I currently have in place to give you all an idea of where I am at.

I wanted to start a new thread on this as I believe more people will be asking about LTE on the ZV9 update. If you are able to get 4G LTE working, please post how you did so!

http://i.imgur.com/vix0aIH.png (band priority screenshot) | http://i.imgur.com/oAgI6MB.png (LTE ##3282# settings) | http://i.imgur.com/XZElcz6.png (phones network settings > mobile networks) | http://i.imgur.com/gR9AiuP.png (LTE Discovery App results)