Last Updated on April 6, 2017 by Mathew Diekhake

The SlimROM development team are managing the latest work based on Android 5.0 Lollipop for some of the Nexus range. That’s all we are seeing for Lollipop to date. In a similar way to what we saw from Cyanogen with CM11, the SlimROM guys are still creating builds based on the later stages of KitKat. Here we have the SlimKat build 8.20 based on Android 4.4.4 for the Samsung Galaxy S3 LTE.

The build is rolling out weekly and refreshing device; we now it’s stable enough to run on the daily phone. You don’t have to install this custom ROM on the secondary phone. if you want to try out a ROM from this team, why not give this one a try? You can see from the official changelog listed here, that it’s had many releases before now. You can install this edition with confidence.

Slim ROMs

Before starting the steps we want to run through some of the essentials. Here you will learn what you need before starting, what the risk are and some applications to help you complete tasks easily.

  • You will lose all the data on the current ROM during the guide. We always wipe the ROM clean when installing a fresh custom ROM. You must take a Nandroid backup after entering the recovery mode. You can do it separately beforehand if you prefer it that way.
  • Moreover, you can take a backup different ways such as installing Titanium from Google Play. There are many ways of backing up the operating system. However, you want to use a way that’s suitable for those of you with root access.
  • Correspondingly, you must have root access before installing any custom ROM. You must follow a guide elsewhere before starting here. Once finished, come back and begin the steps.
  • The USB charging feature takes care of the battery for most modern-day smartphones once they are plugged into the computer. However, since we are only connecting to the computer for a short period, you must make sure there is enough battery on your device to finish the flashing without it turning off. Don’t start until you have at least 50% battery power.
  • You can check the battery level by looking at the battery icon from the status bar.
  • Don’t attempt customizing your device in any way unless you are an advanced Android users with experience. If your device is playing up and you need help you can leave comments. Otherwise try applying a factory reset or hard reset. The Simple factory reset application from Google Play is always a good choice.
  • You must have a custom recovery installed before starting. Choose from ClockworkMod or TWRP.
  • You can use the following for any of the Galaxy S3 LTE variants including the d2vzw, d2tmo, d2mtr, d2att, d2usc, d2spr, d2cri and the d2lte models.
  • Check which model number you have by turning on the device and navigating to Settings > About Device.

How to update to SlimKat Build 8.20 Android 4.4.4 Kitkat on Samsung Galaxy S3 LTE

  1. Download the custom ROM file here.
  2. Download the suitable custom ROM Gapps pack here.
  3. Use the desktop for both of the files. Do not extract the files.
  4. Connect the S3 to the computer and tranfer the files to the internal SD card.
  5. Disconnect from the computer.
  6. Turn off the smartphone.
  7. Boot it back up in recovery mode.
  8. Apply the Nandroid backup now from the menu.
  9. Apply the factory reset from the menu.
    – CWM picks wipe data/factory reset
    -TWRP picks wipe
  10. ClockworkMod users must pick “install zip from sdcard,” followed by “choose zip from sdcard.”
  11. TWRP users choose the “install’ option.
  12. Upload the custom ROM package.
  13. Do the same steps and upload the Gapps package.
  14. Go to the main menu on select “reboot system now.”

Sometimes people regret customizing their devices and wish to return everything back to stock Android. You must have for another official firmware release or software update to arrive. The older the device is the less chance you have of that happening. Software updates stop after a phone reaches a certain age. In those cases you want to unroot the smartphone by using an app from the Google Play Store such as root checker and unroot pro.