How to update Samsung Galaxy S3 to Android 7.1 version GT-I9300

Although it may seem unbelievable and many people think that the world of ROMs is already on its last legs, this is not really the case, since now more than ever with the arrival of Android Nougat or Android 7, thanks to ROMs like the Lineage OS project or what is essentially the continuation of CyanogenMod, today I'm going to show you how to update the Samsung Galaxy S3 to a fully functional Android 7.1 Nougat.

This practical tutorial, in which I show you step by step how to update the Samsung Galaxy S3 to Android 7.1 or Android Nougat , is only for the international model, also known as GT-I9300. Here you will find everything you need to update this still widespread Samsung device, which, much to Samsung's chagrin, can still run the latest version of Android quite smoothly.

Requirements to update the Samsung Galaxy S3 to Android 7.1 Nougat model GT-I9300

Surely you already have your terminal with Root and Recovery modified, in that case skip directly to step number 3:

Have the international model of the Samsung Galaxy S3 GT-I9300
Have the terminal Rooted and with modified Recovery as I show you in this post.
Make a nandroid backup of the entire system through your TWRP Recovery and save it in a safe place on a sdcard outside the Galaxy S3.
Update TWRP Recovery to its latest version available from the official TWRP app or with Flashify. From this link I show you how to download the latest image available from TWRP Recovery and below you will find links to download the apps.
Make a backup copy of the EFS folder from Recovery TWRP itself from the Backup option, checking only the EFS option.
(Optional), make a backup of all your apps and data with Titanium Backup since in the update process everything will be erased.
Enable the USB debugging option from Settings and have the battery fully charged.

Download QR-Code

Official TWRP App

Developer: TeamWin LLC

Price: Free

The app was not found in the store. 

Go to store Google websearch

Files needed to update the Samsung Galaxy S3 to Android 7.1 Nougat (GT-I9300 model).

You will need to download two compressed files in zip format and copy them without unzipping to the internal or external memory of the Samsung Galaxy S3:

Samsung Galaxy S3 update method to Android 7.1 Nougat

Guide image does not correspond to the latest version of TWRP

Once you have completed all the steps I explained in the requirements and downloaded the two necessary files, reboot into Recovery Mode and follow these steps :

Wipe, Select Advanced Wipe y We mark all the options except where we have copied the zip files of the Gapps and the Rom. In other words, if we have copied it to the internal memory we will not select the Wipe from the internal memory and if we have copied it to the external SD Card we will not have to select this path. We mark all the others and slide the bottom bar to perform the requested action.
Install y we select the Zip of the Rom and then move the bar below and the action is executed.
We go back until we reach the option again Install y we select the Zip of the Gapps or native Google applications necessary for the Google Play Store to work and we can download and install apps.
We move the action bar again and when the flashing of the Gapps finishes, we select the option of Wipe dalvick and cache that appears in the lower left right next to Reboot System and above the slider bar.
We slide the bar to make those Wipes and when it is finished we select the option of Reboot System now.

On the first restart, the device will take a little longer than usual to fully boot up . Don't worry, this is perfectly normal; it can take up to ten minutes as the operating system finishes installing. Once it's fully powered on, we'll configure it with our information, such as Wi-Fi and email for our Google account. After that, we'll leave it untouched for about ten to fifteen minutes to allow the new operating system to settle.

After this, we restart it normally , that is, we turn it off completely and turn it back on. This time the restart will be much faster and we can start downloading and installing our favorite or necessary applications.

If you have backed up your apps with Titanium Backup, now is the time to install the application and restore all the apps , although I advise you to download and install everything from scratch for a completely clean installation and better performance of the terminal.

With this, you can now enjoy the latest version of Android on your still valid international model Samsung Galaxy S3.