Check the info in this post in order to complete the installation of a brand new CM 12.1 Android 5.1.1 custom ROM for your Galaxy Premier phone.

The CyanogenMod team has released the first CM 12.1 Stable builds based on Android 5.1.1 AOSP releases. You can learn a whole lot more about these new stable releases here and here.

Before you can start the CM 12.1 Android 5.1.1 ROM on your device you should read the preparation info below:

  • use this post only with the Samsung Galaxy Premier devices.
    - don't attempt to update any other devices with the files that you will find in this post.
  • your Galaxy Premier device needs to be on a rooted firmware.
  • a CWM or TWRP custom Recovery needs to be installed on it, too.
    - make sure that the installed Custom Recovery is updated to its latest version, so that it supports the latest Android 5.1.1-based ROM builds.
  • in the tutorial you will find the NANDROID Backup and the Factory Reset steps.
    - do not skip these steps.
    - the NANDROID ROM Backup creates a full restore point for your device, one that can be used in case the new CM 12.2 ROM doesn't boot in normal mode.
    - the Factory Reset process wipes clean the system partition, but it won't delete any files from the internal storage.
    - the 'factory reset' removes the old ROM and it allows the new ROM to boot in normal mode after the installation is complete.
  • in case you need to save data from installed apps, then you should try to use Helium for Android.
    - sync Contacts info with your default Gmail account.
  • read the entire post and do not skip any steps.
  • this is a post for advanced users, we cannot be blamed in case you brick the device nor in case you lose any important data in the process.
  • check the battery charge level of your device, it has to be over 50% to prevent the phone from powering down during the installation process.

These were all the guidelines you had to go over before continuing to the next part of this post.

How to flash CM 12.1 Android 5.1.1 Stable ROM for Samsung Galaxy Premier:

  1. Download the CM 12.1 Snapshot zip from here.
  2. Download Gapps for Android 5.1.1 ROMs here.
  3. Move the downloaded files to your Galaxy Premier's internal storage.
    - after the files are copied you can disconnect the device from computer.
    - do not extract the zip archives.
  4. Switch off your phone.
  5. Boot it in Custom Recovery Mode.
  6. First, create a NANDROID Backup:
    - CWM: select 'backup and restore'.
    - TWRP: select 'backup'.
    - confirm.
  7. Now you can factory reset the Galaxy Premier:
    - CWM: select 'wipe data/ factory reset'.
    - TWRP: select 'wipe'.
    - confirm the factory reset and continue to the next step when done.
  8. Start the CM 12.1 Android 5.1.1 ROM installation:
    - CWM: select 'install zip from sdcard', then 'choose zip from sdcard'.
    - TWRP: select 'install' option.
  9. Find the CM 12.1 Snasphot zip and confirm the flashing process.
  10. Install the Gapps zip too, but after the new ROM has finished installing.
  11. Reboot your device in normal mode after all the new files are successfully flashed.

I hope that you've managed to complete the CM 12.1 Android 5.1.1 ROM installation on your device. In case you need any extra help you should use the comments field below.

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