catch 142 times in the forum for all topics about samsung written) Here's an example taken from here Samsung GT-I9300 Galaxy S III - Official Firmware (Post # 14648077) and slightly processed under our device
1. Put the Samsung Kies from the Samsung website. It is necessary to have appeared on a computer driver. You can put the driver only.
2. Run Kies, connect the phone to a computer. Will begin downloading the driver. After they download Kies sees your phone. If Kies found your phone, you can disconnect it from the computer. If you want, you can save the phone before disconnecting any information via Kies (contacts, notes, messages, etc)., Because in the future it is all erased.
3. Switch off the phone, close Kies.
4. Download the Odin 3.09.
5. Download the correct firmware
6. Turn off the phone.
7. Press the Home key, key, volume down, power key. Loading firmware download mode. Push-button volume up to continue. All are now in the phone firmware download standby mode.
8. Run the downloaded previously Odin 3.09, jackdaws, no do not touch (the default stand AutoReboot, F.Reset Time), in the PDA field to embed your flash file, .................. ................. tar.md5 (File SS_DL.dll, which is also stored in the archive with the firmware is not needed, it will not have to put)
9. Connect your phone to a computer.

Stop and check everything: At the moment you closed on your computer Kies, Odin Odin is opened, the phone in Download mode (with the robot picture), the phone is connected to the computer and on the computer loading the driver again. After you download the drivers in the Odin-e appeared at the top of the left blue box, from which it is clear that the phone is connected. ": [COM12] 0" (the number after COM can be different) type of inscription there appears. So everything is ready.
10. Push in the Odin-e Start.
11. Waiting for about 15 minutes.
12. When the process is complete, in Odin-e Pass appears. Turning off the phone from the computer.
13. The phone will reboot in normal mode, but the old stuff from the old firmware was, glitches began possible. Turn off the phone.
14. Push-button Volume up, Home, power key.
15. In the pop-service menu perform Wipe data / factory settings and then Wipe cashe Management Volume keys (up and down), and the choice of the power key. These actions remove the old stuff from last firmware. Deleted everything. That is, all data on the internal flash drive, all the settings and so on. Remains bare new (which you set) firmware (as when you bought your phone).
16. Select Reboot or Restart (do not remember exactly what it says, well, in general reset).
17. The phone rebooted and turned on will prompt you to select a language, time and etc. (That is, as when first turned on) All you clean like flashing the store. We skip all the settings and exit to the desktop
18. To check the changed region or a region is not again go in rekaveri mode (Press until you reach the volume-up button, Home, power key.) Where the bottom is due obyt written about the following --Appling Multi-CSC ... Applied the CSC-code: BTU, this means that the region has changed to England succesfully applied multi-CSC
19. Again, all wipes are doing and set up your phone as you like