Phone must be rooted to update
For Root a phone use this : ftp://shortfuse.org/SuperOneClick/Packages/SuperOneClickv2.1.1-ShortFuse.zip
Android 4.0 download link :- http://tanguy.forumdoandroid.com/ics/
Rom Manager:- https://market.android.com/details?id=com.koushikdutta.rommanager