Please read the FAQ!
First you have to download the files: http://forum.xda-developers.com/show...&postcount=207
1. Power phone off.
2. Press Volume down+Home+Power key to enter download mode.
3. Press volume up when prompted.
4. Make sure you have the drivers all installed and connect the phone to pc.
1. Select pit file
2. Select CODE_I8160XXMB2_932015_REV00_user_low_noship in the PDA field
3. Select CSC_OXA_I8160OXAMB2_932015_REV00_user_low_noship in the CSC field
4. Let re-repartition, Auto reboot and f. reset time ticked.
5. Press start and wait until it finishes.
Congrats, you are now running the latest android software!!!
1. Should I flash this firmware?
It's your own choice, this is a before release leak and i am not responsible for any damage you do to the phone.
2. Can I flash this if i am from outside europe?
The pit file is for europe only, you can try but it might give you an error, until someone figures out how to modify that file, you are stuck.
3. How do I root my phone?
4. My phone is discharging too fast. Help!
Install No Frills CPU Control (root) from the market and set the minimum frequency to 200.
5. Can I go back to Gingerbread?
Not for now. Someone with a working gingerbread phone has to figure out how to extract the gb pit file but flashing back can be a very dangerous operation.