if you get stuck with any of this call me !!
download Odin 1.7 and Pitfile 512
download firmware jvk 2.3.3
extract jvk 2.3.3 gingerbread in the same folder (password is) samfirmware.com
1. make sure your pc has the usb drivers for the phone !! (make sure it connects to kies ) if you have the drivers close kies!!!!!!!!
2.Switch Off your Galaxy S. Make sure it’s disconnected from PC and connect it only when told.
3.Now, put it in Download Mode. For that, press and hold these keys together – Volume Down + Power Button + Home Button.
4.Now, head over to Odin (double-click to run the program on computer) and place the files as per the instructions given in steps 5,6
5.in the pit file box place pitfile 512
6.In the PDA box, select this file — PDA_XXJVK.tar.md5
7.In the Phone box, select this file — PHONE_XXJVK.tar.md5
7.In the CSC box, select this file — CSC_OXAJVK.tar.md5
8.Make sure to check ‘Re-Partition’.
9.Keep ‘Auto Reboot’ & ‘F. Reset Time’ boxes checked.
10.Now connect your phone (which is in Download Mode since step 2) to computer.
11.Upon connecting, Odin will show “Added” under the message box.
12.Now, hit the START button to let the process begin.
13.When process at Odin finishes your phone will automatically reboot. You can disconnect your phone from PC when reboot finishes (it may take 3-4 mins just leave it).
14.When your phone has restarted, you are on the XXJVK Android 2.3.3 Gingerbread ROM