Here’s a post I made in a forum earlier…thought it would be useful…
Hey guys…I’m a long time user first time poster…I have an O2 UK N81 8GB RM-179. It was previously on a debranded v 11.0.045 which i recently upgraded to v20.0.056..If anyone’s debranded an n81 8gb before its pretty easy and the same method. This guide’s for the noobies or for people who just need the product code
1. Firstly, we need to change the product code of the phone to 0557872. All I know is its English. Don’t know the other languages included in it. The procedure is as follows:
The procedure to change the product code is the follow, but be careful! The warranty of the phone will be lost and the operation is dangerous:
– Download and install Nemesis Software Suite (called also NSS) from http://www.b-phreaks.co.uk/files/NSS/NSS103814.zip
Now you can update your phone using Nokia Software Updater, who will detect automatically the new product code, and the new firmware without operator brand and with English and Italian languages.
This procedure is useful if you bought your phone outside your country, without or with limited warranty and you would like to change language to English or Italian and take off the operator brand variant. Be careful! Following those steps you can violate the contract with your operator and, however, you will lost the warranty.
This procedure will NOT disable any OPERATOR LOCK nor SIM LOCK.
2. I followed this guide and changed my product code to 0557872.
3. Next, I upgraded my Nokia PC Suite and Nokia Software Updater to the latest versions from the Nokia website.
4. Next, I took appropriate backups of my phone (just in case anything happens). Although this step isn’t completely necessary because the software update doesn’t wipe out your existing data and settings.
5. Next, connect your phone to the PC via USB in PC Suite mode and check for updates. It should tell you there’s one available.
6. Start the update!
DONE! Note that if you want – for safety reasons – change your product code back to the old one found below your battery on the phone on a sticker (should be 05xxxxx) just in case anything happens to your phone in the future and you plan to send it back to a service centre for repair. I’ve sent it back once after debranding and they don’t complain about the warranty! Tell them you got it like this from ebay
Hope this helps!