1. Perform a full system backup to your computer
2. Fully charge your Sony Ericsson P1i battery
3. Open the Sony Ericsson Update Service
4. Press Start
5. Press Accept to agree to the Terms of use
6. Select the PDA-looking (with stylus) image
7. Press Continue
8. Select P1
9. Press Continue
10. Connect the USB cable to your computer
11. Turn off your Sony Ericsson P1i
12. Remove and reinsert the Sony Ericsson P1i battery
13. Press and hold the C button while connecting the USB cable to your Sony Ericsson P1i
14. Continue holding C button until prompted to release
15. Press Upgrade

You have now upgraded your Sony Ericsson P1i to the latest release.