Introduction: Installing LineageOS on Samsung Galaxy A3 (2016)
Smartphones are a great invention and make life a lot of easier. However, the rampant data collection activities of smartphone operating systems and apps are a nuisance. Alas, there are people out there working on alternatives such as LineageOS, an Android distribution free of Google.
This instructable shows you, how to install the LineageOS operating system (custom ROM) on a Samsung Galaxy A3 (2016). The way of approaching it might also work for other Samsung Galaxy devices, but without any warranty.
Step 1: Charge Phone and Install Samsung USB Development Drivers
Fully charge your smartphone up to 100%. Next on your PC, uninstall any previously installed Samsung software and drivers, such as Samsung Kies.
From the Samsung homepage, get the latest Android USB drivers for development and install them: https://developer.samsung.com/galaxy/others/android-usb-driver-for-windows
After the installation has finished, restart your PC.
Step 2: Installation of a New Recovery System
The given recovery system of Android is not good enough. We need to install a better one, which allows for 1) backing up the existing system and 2) flashing the new one. We will use a tool called "TWRP" for this, and an installation method for TWRP, which does not require root (so-called Odin install method, see https://twrp.me/samsung/samsunggalaxya32016exynos.html).
All in all, it is important to get the correct version of TWRP that fits to your phone, see https://twrp.me/Devices/. The latest version for the A3 (2016) can be found here: https://eu.dl.twrp.me/a3xelte/ . Make sure to download the latest tar-compressed image, since the installation tool for the recovery system works only with tar-files.
The installation tool we will use is Odin. Get it from a trustworthy source such as https://www.droidviews.com/download-odin-tool-for-samsung-galaxy-devices-all-versions/ and be aware of the fact, that there might be sites out there just spreading malware with their Odin downloads.
Unzip all files to the same folder and move the TWRP img.tar-file into this folder.
Now run Odin by double clicking on the exe-file.
Click on the button "AP" and choose the TWRP tar file.
Switch to the "Options" tab and deselect "Auto reboot".
With the smartphone powered off, hold "Volume Down + Home + Power" to enter "Download Mode". Accept the disclaimer, that installing a "custom ROM" is something critical. Connect the phone via USB to the PC.
In Odin you should now see a blue bar showing up above the "Options" tab named something like ID:COM 0:[COM4].
Press "Start". After a while there should be another bar above the blue bar saying "PASS!". Additionally check the "Log" tab for errors. If there a problems during this step, do not disconnect the phone but wait until Odin releases the phone by itself (see "Removed!" in "Log" tab).
Turn off the phone by long-pressing "Volume Down + Home + Power" and disconnect it from the PC.
Switch the phone on again and immediately press "Volume Up + Home" to prevent the stock ROM from removing the newly installed custom ROM recovery (for more on that see the notes of the TWRP team on the Odin install method).
You should now see the TWRP recovery system on the screen. Swipe to allow modifications.
Step 3: Backing Up the Existing Stock ROM
Insert an SD card with at least 8GB into the phone. In TWRP, press "Backup". Check all partitions for a complete backup. Press "Select storage" and choose the SD card as destination. Swipe to backup.
Press "Back". Make another backup of the EFS partition only.
Press "Back". Make a last backup of "Boot", "Data", "System".
Click the "Home" button, choose "Reboot" and "Power off".
Remove the SD card from the phone and copy the backup files to your PC for later usage.
Step 4: Install/flash LineageOS
From https://download.lineageos.org/a3xelte get the latest LineageOS version for the A3 (2016). Empty the SD card and create a folder "Install". Copy the LineageOS zip-file to this folder. Next, insert the SD card back into the phone.
With the smartphone powered off, hold "Volume Up + Home + Power" to enter "Recovery Mode". Click "Wipe" then swipe to factory reset.
Now tap “Format Data” and continue with the formatting process by typing "yes". This will remove encryption as well as delete all files stored on the internal storage.
Press the "Home” button. Choose "Wipe" "Advanced Wipe", then select “Cache” and “System”. Swipe to wipe.
Press "Home" again and choose "Install". Click "Select storage" and select the SD card.
Click on the folder "install" and mark the lineageos.zip-file. Swipe to confirm the flash.
After the installation has finished, click "Reboot system".
Step 5: Customize
Customize LineageOS, e.g. install the F-Droid Store to download free and open software apps to your phone. Most other popular, proprietary apps can be found on APKMirror, a trustworthy source for popular Google Play Store apps.
On APKMirror you can find an app called "Exodus Privacy" which informs you about data gathering activities of apps on your phone. Even better: Check apps in advance before installing them via https://exodus-privacy.eu.org/, https://search.appcensus.io/, https://www.appbrain.com/app/appbrain-ad-detector/com.appspot.swisscodemonkeys.detector.
If you can't get arround a tracking app: On the F-Droid Store, you can find an app called "Blokada" which prevents in-app tracking, see https://blokada.org
All in all, as of September 2019, a good offline alternative for Google Maps seems to be "Magic Earth”, a free maps and navigation app by General Magic. The app has been tested and recommaned by https://mobilsicher.de, a project dedicated to mobile security funded by the German parliament and ministery of consumer protection.
Step 6: Done!
We are done! Enjoy your new LineageOS system. And by the way: If you found this instructable inspiring and life-enhancing for you, you can also buy me a coffee :-).