Galaxy s2 ROM replacement (2)

Root the device first, guide here

This does need some technical knowledge and i cannot be responsible if you brick your device, I've done it and it works :)

This process will invalidate your phones warranty!

Once your phone is rooted, download the ROM you want, in my case i went for cyanogenmod stable v9.1 because its quite established and a good support forum.

You will also need the google apps package on the external sdcard, this contains the play store etc.

Method via Recovery - original instruction source

1. Download the latest version of CyanogenMod.

2. Optional: Download the Google Apps for the device.

3. Place the CyanogenMod update.zip file on the root of the SD card.

   Optional: Place the Google Apps .zip on the root of the SD card also.

4. Boot into the ClockworkMod Recovery.
5. Once the device boots into the ClockworkMod Recovery, use the side volume buttons to move around, and either the power button or the trackball to select.

   Optional: Select backup and restore to create a backup of current installation on the Samsung Galaxy S II.

6. Select the option to Wipe data/factory reset.
7. Then select the option to Wipe cache partition.
8. Select Install zip from sdcard.
9. Select Choose zip from sdcard.
10. Select the CyanogenMod update.zip.

    Optional: Install the Google Apps by performing steps 7 - 9 again and choosing the Google Apps update.zip.

11. Once the installation has finished, select +++++Go Back+++++ to get back to the main menu, and select the Reboot system now option. The Samsung Galaxy S II should now boot into CyanogenMod!