1. Root
Root using WugFresh Toolkit
http://forum.xda-developers.com/showthread.php?t=1766475
http://www.wugfresh.com/dev/nexus-root-toolkit/ (NexusRootToolkit.v1.5.2.sfx)
Had trouble with installing the USB drivers for Nexus S 4G. Had to install USB drivers manually from what was packaged with the toolkit.
2. Backup current rom using CWM Nandroid
Install RomManager using Google Play
3. Using the Toolkit -- Advanced, installed the Touch CWM Recovery
http://www.clockworkmod.com/rommanager
4. Installed AOKP ROM ICS 4.04, and latest GApps for ICS 20120429
http://forum.xda-developers.com/showthread.php?t=1433863
http://goo.im/gapps/gapps-ics-20120429-signed.zip
5. Installed Matrix Kernel
http://forum.xda-developers.com/showthread.php?t=1361478
