How ToMods

Update Galaxy S2 I9100G to Android 5.0.2 Lollipop via CyanogenMod 12 Nightly ROM

Samsung will not release the official KitKat or Lollipop updates for the Galaxy S2 smartphone due to hardware limitations but still you can taste the sweetness of Lollipop on your S2 using custom ROMs. Android 5.0 has been rolled out for most of the Samsung’s flagships and you’ll be glad to hear that Galaxy S2 I9100G is one of those few lucky Android devices that can be also upgraded to the latest Android 5.0.2 Lollipop via CanogenMod 12 custom ROM to customize and personalize your Galaxy S2.

Remember that this version of CM12 is not officially released by Samsung or Google but is just a custom ROM which is developed by the xda-developers and is only based on stock Android Lollipop that comes with a lot of extra features, apps and a custom UI that you can’t find on the stock Android platform. This CyanogenMod 12 Nightly ROM is stable and can be used as a daily driver. Many users have flashed and tested this CM12 ROM on their Galaxy S2 devices and they reported that the firmware is running without any issues. You’ll need a custom recovery already installed on the phone to flash this CM12 ROM on it.

Updating Galaxy S2 I9100G to Android 5.0.2 Lollipop via CyanogenMod 12 Nightly ROM

So if you want to get this latest custom ROM on your handset then follow the given guide on how to Update Galaxy S2 I9100G to the latest Android 5.0.2 Lollipop with CM12 Nightly custom ROM to improve its performances and customize the Android experience to run on your smartphone.


This guide having these instructions is only working with the Galaxy S2 GT-I9100G (international variant). Do not try to install this ROM if you have a different device. You can check the model number of your Galaxy S2 by going to Settings > About Phone


AndroidBlog will not be responsible for any damage or lose occurred to your Galaxy S2 I9100G during or after the installation of CM12 Nightly custom ROM. Proceed at your own risk.


  • Take a proper backup of all your important data and settings before starting the firmware installation process, such as your SMS, MMS, APN Settings, Call Logs, Contacts and media contents etc.
  • Enable USB Debugging Mode on your S2 by navigating to “Menu – Settings – Developer options”.
  • Your Galaxy S2 must be rooted with the latest custom recovery image (CWM or TWRP recovery) already installed on Galaxy S2.
  • Make sure that you’ve properly installed the correct Samsung Galaxy S2 USB drivers on the PC.
  • The bootloader of your Galaxy S2 must be unlocked
  • Ensure that your phone has at least 80% of battery charge before proceeding to the firmware installation guide.

Required Files:

  • CyanogenMod 12 Android 5.0.2 ROM for Galaxy S2 (GT-I9100)
  • CyanogenMod 11 Nightly ROM for Galaxy S2 (GT-I9100G)
  • Google Apps

Steps to Install Android 5.0.2 Lollipop via CyanogenMod 12 Nightly custom ROM on Galaxy S2 GT-I9100:

Follow the given step-by-step guide to install CM 12 Nightly Build on the Galaxy S2 manually:

1:- First, plug your Galaxy S2 to the PC via its USB data cable and mount the USB mass storage of the device.

2:- Transfer the Android 5.0.2 CM12 ROM .zip file that you’ve already downloaded from the above link, to the root folder of your SD card on the phone.

3:- Disconnect the device from the PC and turn it OFF Power off the phone and disconnect its USB cable from computer.

4:- Turn ON the device while pressing and holding Volume Up + Home + Power keys at the same time.

5:- While your device is now in CWM Recovery, perform a full data wipe by selecting Wipe Data/Factory Reset, Wipe Cache Partition and Wipe Dalvik Cache as well by navigating to ‘Advanced’ > Wipe Dalvik Cache.

6:- Go back to the main recovery menu and choose Install Zip from SD card > Choose Zip from SD card.

7:- Navigate to the CM12 ROM .zip file that you’ve already transferred to the root folder of your SD card and confirm the installation process to start.

8:- Install Google Apps (Gapps) package by repeating the above given steps once the ROM installation is completed.

9:- After installing the ROM and Gapps on the phone, go to “+++++Go Back+++++” and from the Recovery Menu, select Reboot System Now.

This will reboot the device and may take some time about 4 to 5 minutes while booting up for the first time after installation.

Done! You’ve successfully updated Galaxy S2 I9100G to the latest Android 5.0.2 Lollipop with CM12 custom ROM.

Do let us know in the comments area below if you have any trouble or query while installing CM12 Nightly custom ROM on your Galaxy S2 to get the latest Android 5.0.2


Aamir Jamal

An Android Geek and audiophile who love to read and write reviews/tutorials about gadgets and new tech stuff. He has written 1007 guides and other posts.

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  1. Hello PrebuitGmsCore.apk file installations giving ‘there was a problem while parsing the package’

    samsung galaxy s2 i900G.

    Please help me since i have need to have CorePrebuiltApps

  2. When I install this MOD, everything goes well, but when I try to install gapps, I get an error code 70 saying that there is not enough free space in the system partition to install it. I have tried prettymuch everything to try and get it to work, but with no success. Is there any way to resize the /system partition?

  3. Now to my own issue: Which version of the Google Play Services are you guys running the S2 / Lollipop?
    – I have tried xxx-430 (universal armeabi-v7a) and xxx-434 (240 DPI & armeabi-v7a)
    – I could not find the xxx-414 (240 DPI & armeabi) nor xxx-410 (universal armeabi)

    If any reader has it running on S2 / Lollipop please let me know the exact version of your Google Play Services as displayed in app manager… thanks!!!

  4. @Laurent: version 6.7.76 works for me.

    The first link is not for a i9100g variant but the second is although it’s CM11 KitKat. I use an i9100g updated my firmware from JB to CM11 nightly ROM available on the page. It installs a 4.4.4 KitKat and not a Lollipop. Not complaining but with the CM11 KitKat, my galacy S2 works like a gem. Thanks.

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