Install CyanogenMod For The SG S2 (I9100G)

[munkee]

Requirements:

• This tutorial is for advanced users, if you don’t understand what you are doing, do not proceed or you will brick your phone.
• The devise has to be Rooted and the CWM Recovery needs to be installed on it.
• USB Debugging from the Developer Options must be enabled.
• Your phone’s battery must have enough power left. In case your device powers off while you’re flashing the new ROM, then you will be forced to repeat the entire tutorial once again.

Pre-Installation Notes:

• Installed Apps, SMS, Call Logs, etc ... will be removed, so you can use Helium app or Titanium Backup to backup your installed apps and SMS backup & restore, Call Logs backup & restore and APN Settings Backup & Restore to backup your SMS, Call logs and APN Internet Settings. (Root access must be granted for some oh these tools).
• Remember to sync your Contacts info with your Gmail account. This will backup all your saved phone numbers to your Google profile so you can restore them after the new ROM is flashed with success.

Tutorial:

1. Download the latest build of Cyanogen Mod version Here. (Do not extract the files).
2. Download Gapps for Android custom ROMs Here. (Do not extract the files).
3. Connect the smartphone to your computer using the USB cable.
4. Copy & paste Cyanogen Mod and Gapps to your smartphone internal storage.
5. Disconnect the smartphone from your computer.
6. Power off your smartphone.
7. Boot the Galaxy S2 I9100G into Custom Recovery Mode by pressing Volume Up + Home Button + Power Button together. Once the Samsung Galaxy logo appears release all buttons.
8. Once the CWM menu is shown you need to create a Nandroid Backup of your current ROM. Select “Backup and Restore” option then use “Backup” and save the nandroid file to your device’s internal /external storage.
9. Now you have to apply a factory reset. select “Wipe Data/Factory Reset” then confirm.
10. Install the Cyanogen Mod custom ROM. select “Install zip from sdcard” or “Install zip from Internal Storage” if you don’t have an external SD Card mounted to your smartphone then find the Cyanogen Mod ROM file and install it then confirm the process.
11. After the ROM is installed you need to flash the Gapps file. Use the same actions as in step 10 but instead of flashing the ROM file you need to flash Gapps.
12. When the installation is complete you will need to get back to the main CWM recovery screen and reboot the device.
13. The Cyanogen Mod first boot process will take at most ten minutes to complete then you will see the Cyanogen Mod home screen.

Post-Installation Notes:

• If the device doesn’t boot into normal mode with the new ROM and you didn’t apply factory reset, then you should return to step 9 and apply it.
• You shouldn’t press any buttons while Cyanogen Mod and Gapps are installing, just wait for the process to finish before applying the next step.
• In case you don’t like the Samsung Galaxy S2 I9100G performance while running Cyanogen Mod ROM, then you should use the Nandroid backup file created in step 8 and restore your device to its previous ROM.
• You can check for updates by navigating to Settings > About Phone > Cyanogen Mod Updates.

[stylemessiah]

Not being ungrateful, but theres an entire website called XDA Developers

http://forum.xda-developers.com/

that every sane person with a phone/tablet uses for this info and it offers support for any problems you may encounter

Not many people come here looking to flash Android ROMs, its a PC site :)

[johndoe]

one caveat to the OP in regard to backups.

I had the experience of installing CM10.1 (4.2.2) on two identical (as far as hardware) S2 phones in late December 2013/early January 2014. One phone belonged to my brother and was already on stock Samsung JB (I think v4.1.2), the other one was his wife's phone but was still on Samsung stock GB (wouldn't update OTA to ICS or JB).

Well, anyways, I took titanium backups of the data from both phones and flashed Dorimanx kernel and CM10.1 on both phones. When it came time to restore titanium backup data on both phones, while the phone originally on JB was a piece of cake, I could not restore anything on the phone which had been upgraded from GB. So, in case migrating your personal stuff is important, use multiple different software to backup your data prior to taking the plunge...

[PrEzi]

johndoe -- Actually TB is perfect but you need to keep in mind -- DB (Data) is quite differently structured between GB and JB/KK -- I _never ever_ advise to restore system apps nor settings coming from a different version of ROM. Restoring user apps (eventually +data) is fine.

For contacts/sms/etc. you can use XML export in the main menu of TB (or better even - use a free app called sms backup & restore).

And actually - indeed XDA is one of the best sources for any Android/Custom ROM things and problems.