Update AT&T Galaxy S3 to Marshmallow 6.0.1 using a Custom ROM

The Samsung Galaxy S3 from AT&T has now received the Android 6.0.1 Marshmallow. Even though the update is not official from Samsung, the firmware has only some bugs however is running great without any lags.AT&T Galaxy S3

This custom ROM is named OctOS and developed by those XDA-Developers. So, we should thanks them for the firmware and for this step by step guide.

Before we proceed with the guide you should check some requirements from below in order to complete the installation process with success.

  • Use this guide only with the AT&T Samsung Galaxy S3 I747 variants.
  • Make sure you have rooted your AT&T Galaxy S3 and installed a custom recovery like TWRP on it.
  • You need to install Samsung Galaxy S3 driver on your computer.
  • Plug in charger the device if the status bar shows less than 50% power left.
  • Read the whole article and do not skip any steps.

We at Techxat, are not responsible in case you damage or brick your phone during the installation process. If you are interested to complete apply the steps from below you will lose the warranty of your AT&T Galaxy S3.

Required Files

Download OctOS Marshmallow ROM Download Google Marshmallow Gapps

How to Install Android 6.0.1 Marshmallow on AT&T Galaxy S3

  1. Download the required files from above and place them on desktop.
  2. Transfer both files to the phone’s internal storage via USB Cable.
  3. Power it off and enter it into recovery mode.
  4. When in recovery mode, from there perform a Nandroid Backup because during the installation process you will lose all your personal data.
  5. When you’re ready, perform a hard reset. From the TWRP main menu tap on the wipe button and select Advanced Wipe. Then select all Dalvik cache, System, Data and Cache options
  6. Go back to Recovery main menu and tap on the install option. Find the OctOS Marshmallow ROM and install it.
  7. Then using the step 6 install Marshmallow Gapps.
  8. Reboot your phone.

Congratulations; You now know how to update AT&T Galaxy S3 to Marshmallow 6.0.1 with OctOS ROM. If you have any questions feel free to use the comments box.