All set? Let’s start
First we will download and install the LG Drivers program to find on the website of LG. Once installed open it and plug the phone to ON we installed the drivers on the PC.
After installing the drivers of the phone, close the LG Driver and open the Odin 3 program, preferably as an administrator (right-button Open as administrator) and turn off the phone.
Now let’s turn your phone into DOWNLOAD mode, which is the way we should go to flash the device. How do we do it? Very simple, press the following combination of buttons: VOLUME DOWN + CENTER BUTTON + POWER BUTTON and we will turn the phone on the next screen:
Press the VOLUME UP button and you’re in download mode:
The next thing to do is plug your phone to PC to install drivers from the download mode, when the connection is correct we will mark this box:
Easy, no? Well now let the ROM that you downloaded and extract the zip in an easy to locate. Once this is done we go to Odin, we click on the PDA box and select the file extension .md5 and check that everything is as in the following
Press “START” and waited about 10-15 minutes for it to finish flashing. When finished, the phone will reboot and Odin we will mark it with this box in green:
So far the process does not delete user data, but applications to remove operator must restore the data as follows (if you were coming from a free ROM and just wanted to upgrade, you can skip this step):
1) We turn off the phone.
2) We enter the recovery mode by pressing VOLUME UP KEY + + ON CENTRAL BUTTON. To move into recovery mode use the volume keys to raise and lower and middle button or the power button to select.
3) Select “Wipe data factory reset” and “Wipe cache partition”.
4) Select “Reboot system now”
Once you set up your Google account you can restart the phone a few times to seat the ROM.
Finally remind you that what we have to do is install a free ROM not unlock your phone, that is, if you bought it with Movistar not have the ROM but you can only use Movistar SIM.
We have updated our LG G3 to 4.1.2, if you also want to be able to root then follow this excellent tutorial.
Any doubt shall be resolved in the comments. Enjoy this wonderful device!