First things first:The steps below are for academic use only. Actual use on the phone may cause your phone to stop working!!!
1. Install the latest release of Nokia PC Suite
2. Download & Install Nokia Software Updater
3. Download & Install Nemesis Service Suite
4. Connect your phone and wait for Windows to detect it – takes a few minutes, be patient.
5. Open Nemesis Service Suite and click ‘Scan for new device’ on the right-upper part of the window
6. Click on the icon ‘Phone info’
7. Click on ‘Scan’
8. Apart from the other details you can see your current product code. Change this to <a generic code for your phone> and mark the case ‘Enable’.
9. Press ‘Write’, and your phone’s product code will be changed. This is instateneous, if you want to confirm the read, click on ‘scan’ again. The product code box should read the new number you entered.
10. Close Nemesis Service Suite and run the Nokia Software Update.
Do not to touch the cable or the phone while your phone is updating or you will brick it!
Again, if you break your phone, its your own fault. The above procedure will void the Nokia warranty.
List of S60 phones