CyanogenMod 9, based on Ice Cream Sandwich (ICS), has finally landed on the Samsung Galaxy S2 GT-I9100G. Thanks to XDA Developers elite member codeworkx, this ICS-based ROM has found its way to this less than popular variant in the form of a port.

CyanogenMod 9 ROMs are famous for their amazing performance and the customization options which they bring to users, not to mention their built-in theme engine. Now, thanks to codeworkx’s hard work, you can enjoy nightly builds of the Ice Cream Sandwich-based CyanogenMod 9 custom ROM on your Samsung Galaxy S2 GT-I9100G.

The ROM comes with the usual CyanogenMod features, but what makes it amazing is that you get fresh updates for this ROM every time the developers update it. That means, you get the freshest updates almost every night. Keep in mind that nightlies are automatically generated and may contain a variety of bugs that developers are still working on.

If you want to install this ROM on your device, see the requirements and instructions below.

Requirements

• Samsung Galaxy S2 GT-I9100G running ICS firmware and with ClockworkMod Recovery installed
• • For help with updating to ICS firmware, see our guide on upgrading the Galaxy S2 GT-I9100G to official ICS firmware build XXLPQ.
  • For help with installing custom recovery, check out our guide on how to install ClockworkMod Recovery on the Samsung Galaxy S2 GT-I9100G running ICS firmware build XXLPQ.
• A Windows PC
• Download the USB drivers for your phone (SAMSUNG_USB_Driver_for_Mobile_Phones.exe, 23.01 MB) and install them to your PC.
• Enable USB debugging on your phone.
• Backup all personal data on your phone to make sure you have a copy of your personal data (e.g., contacts, SMS, MMS, Internet settings, Wi-Fi passwords, and the like) in case the procedure in this guide erases such data.
• • For backup tips, check our guides on how to sync your data to the cloud and how to create local backups of your mobile data. 
• Make sure that your battery has at least 50% charge to avoid interruption due to power loss. 
• Download Odin3 1.85 (Odin 1.85.zip, 199 kB) to your computer.
• Download the CyanogenMod 9 Resurrection Edition (cm-9-20120420-ODIN-galaxys2.tar.md5, 251 MB) which is required before you install the actual CyanogenMod 9 nightly ROM. 
• Download the latest CyanogenMod 9 nightly ROM for the GT-I9100G to your computer.
• Download the GApps (Google Apps) package (gapps-ics-20120429-signed.zip, 49.6 MB)

Disclaimer

• The instructions in this guide are intended for use with the Samsung Galaxy S2, model number GT-I9100G. Applying these instructions on another device or model may produce undesired outcomes.
• The information in this guide is provided for instructional and educational purposes only. There is no guarantee that these instructions will work under your specific and unique circumstances.
• Use these instructions at your own risk. We shall not hold any responsibility or liability for whatever happens to you or your device arising from your use of the info in this guide.
• Read and understand the whole guide first before actually performing the instructions.

Instructions

You need to install CM9 Resurrection Edition through Odin3 before you can flash the CyanogenMod 9 ROM nightly via ClockworkMod Recovery.

Installing CM9 Resurrection Edition

1. Copy the Google Apps package and the CyanogenMod 9 nightly ROM package file to the root of your Galaxy S2′s internal SD card.
2. Extract the Odin 1.85.zip file to any folder on your desktop.
3. Put your phone on Download Mode by pressing and holding down the Volume Down, Home, and Power buttons together. When the screen turns on, press Volume Up to enter Download Mode.
4. Go to the folder where you extracted Odin 1.85.zip and double-click Odin3 v1.85.exe to launch Odin3.
5. Connect your phone to your computer. If you see an “Added” message in the lower left box of the Odin3 window, your phone has successfully connected with your computer.  If your phone is not recognized by Odin3, disconnect your phone and re-install the device drivers.
6. In Odin3, click the PDA tab and select the cm-9-20120420-ODIN-galaxys2.tar.md5 (CyanogenMod 9 Resurrection Edition) file.
7. Click the Start button in Odin3 to start the flashing. Wait for it to finish.
8. Once the flashing is done, you should get a PASS message with a green background in Odin3. You can disconnect your device from your computer and proceed to the flashing of the ROM.
9. However, if you get a FAIL message or Odin gets stuck, do the following:
   • Disconnect the phone from your computer.
   • Close Odin3.
   • Remove and re-insert the phone’s battery.
   • Start from step 3 again.
10. Your phone will reboot into ClockworkMod Recovery after the flashing.
11. Select Install ZIP from SD Card > Choose ZIP from SD Card. Select the gapps-ics-20120429-signed.zip to install Google Apps Package.

Installing CyanogenMod 9 Nightly ROM

1. Go to Settings > Storage > Menu Key > USB Connection on the phone and select Mass Storage.
2. Copy the CyanogenMod 9 nightly ROM ZIP file to the root of your Galaxy S2′s internal SD card using a USB cable.
3. Turn off your phone.
4. Boot your phone to ClockworkMod Recovery by pressing and holding down Volume Up, Home, and the Power buttons. Let go of them when the screen turns on.
5. Select Install ZIP from SD Card > Choose ZIP from SD Card. Select the CyanogenMod 9 nightly ROM package to install it.
6. Once the installation is complete, reboot your phone by selecting Go Back and Reboot System Now.

Great! You’ve now installed the latest CyanogenMod 9 nightly ROM on your Samsung Galaxy S2 GT-I9100G. Every time a new nighty is released, you can simply flash it through ClockworkMod Recovery. Enjoy the nightly updates.