Pre requisites and Instructions:
1. Before you start flashing make backups of phone specially contacts, photos, text messages, videos and music files. Please remember phone will be formatted during the process and the data will be lost. Anything which is in SD card will not be lost, so you can alternatively move to SD Card.
2. Remove the SIM card as well as the external SD cards if any in your phone. This is advisable.
3. Now, ensure that you keep some things handy like USB cable which you have got with GT I9003 and also the device,
4. Most importantly you need to ensure that your phone has at least 60-80% of battery power left, this is just an advisory which if followed then you will not experience any difficulties as while updation of the device the battery consumption is at a maximum.
5. Ensure that you have administrative rights for computer / laptop which runs on a XP, Vista or Windows 7 OS to download and install the software including the drivers and also along with this you will be requiring the USB port on your computer which supports USB 2.0.
6. Check if you can get into the download mode which is the top most necessity for updating your device. For those whose devices unable to get into the download mode and the recovery mode follow instructions here.
7. Download Odin (program required to push updates files to device and usb drivers (if kies is installed you will not need drivers) from http://www.samfirmware.com/WEBPROTECT-programandroid.htm
8. Download available gingerbread firmware and pit (partition information table) file from http://www.samfirmware.com/WEBPROTECT-i9003.htm. Unzip this file to get either one(pda or code file) , three(pda,csc and phone or modem) or four files(boot,pda,csc and phone files).
9. Ensure that you have closed the KIES completely and also disable any firewalls if any.