The CM 12.1 custom ROM is a replica of Android 5.1.1 Lollipop OS by Google. It also replicates all the features of an Android Lollipop OS like security, the material design user interface and all. The new CyanogenMod custom ROM also gives you some extra options to tweak your phone’s interface and performance. To install this ROM on your Samsung Galaxy Skyrocket phone, just follow this guide carefully and gather all the tools required.

You need a PC with internet connection, a USB cable to connect your phone to your PC and your phone rooted and custom recovery installed, recommended recovery is TWRP and make sure its latest so it can support Lollipop custom ROMs.

CyanogenMod Team

Backup all of your important data stored on your phone because it will get wiped during installation of this custom ROM. Sync all of your contacts to your Google account — this will keep them safe. Backup your important apps using the Titanium Backup app available for free on Google Play Store. If you have a custom recovery image such as TWRP or ClockworkMod already installed, we suggest taking the NANDroid backup.

This installation process is only for AT&T Samsung Galaxy S2 SGH-I727 only do not perform this installation process on other Android device.

Steps to install CM 12.1 custom ROM on AT&T Samsung Galaxy S2 Skyrocket SGH-I727:

  1. Download the CM 12.1 custom ROM zip file on your PC and put it on desktop. Do not unzip those files as we have to use them as it is.
  2. Navigate your PC’s browser to this page and download the Google apps zip file that is compatible with CM 12.1 custom ROMs.
  3. Now turn your phone off by pressing and holding power key for 3 sec and select “power off” from power menu.
  4. Wait till your phone goes off completely and boot it into recovery mode by pressing and holding power key, volume up key and home key together till you see recovery mode.
  5. In recovery mode first take backup of previously installed ROM, tap on “Backup” and confirm.
  6. After that come back to the main menu and tap on “wipe” and confirm the step to revert your phone to factory settings, this will also wipe all the data stored on your phone’s memory.
  7. Now finally tap on “install”, select the CM 12.1 custom ROM zip file and confirm to install it on your phone.
  8. After that, repeat the 7th step with Google Apps zip file, do not wipe anything this time.
  9. After installation’s done come back to the main menu and tap on “Reboot” followed by “System”, this will reboot your phone to OS mode.

Now wait for some time and you will see the welcome screen and you know what to do after that. And feel free to contact me using the comment section below.