Yes I Can!

How-To Install CyanogenMod 9 Alpha 11 Android 4.0 ICS On Nexus S And Galaxy S

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Step 1: Hopefully you’ll already be running an earlier version of CyanogenMod. If you are, skip to Step 3. If not, proceed to Step 2.

Step 2: Root your Nexus S or Galaxy S, you might have to Google around for the latter. It’s an easy task but with quite a few steps. Return to this guide after your devices is rooted.

Step 3: Be sure ROM Manager is installed then open it on your device. Verify that ‘ClockworkMod Recovery’ has the latest version installed.

Step 4: Back up your data. While still in ROM Manager, scroll down and select “Backup Current ROM”. Once completed the backup can be found in your SD card under ‘clockworkmod’ directory. It may be a good idea to transfer this data to your computer in case you need to restore to an earlier state.

Step 5: Install ICS by selecting “Install ROM from SD Card” in the ROM Manager menu.

Step 6: Select “Wipe Data and Cache”.

Step 7: Select “Wipe Dalvik Cache”.

Step 8: Repeat the Steps 3 to 7, but this time with the Google Add-on files.

Your phone will automatically restart. After it reboots.