Debranding your n8: Remove alle the garbage the operators put on your phone!!!
Follow the step by steps instructions and install the cracked uda (so you won't have trouble installing unsign .sis and won't have to sign them yourself before... blablabla)
You have to have this version of phoenix 2010.8 to install the cracked uda (the cracked UDA is the only way atm to jailbreak your n8, to install all games or applications (signed or unsigned))
DOWNGRADING IS NOT POSSIBLE!!!
Don't try to install an older version on your n8
It will just flash it dead...
Use dead phone flashing to get it back to life..

Please perform this operation on your own RISK!
Remove Your memory card, if any, while flashing
Insert it back after flashing, but delete private, resource, sys and system folders from it (memory card) before inserting it back
1) Download and install Phoenix 2010.8
http://www.megaupload.com/?d=HF2NA53Z2) Download navifirm 0.4
http://www.megaupload.com/?d=I23DD2GXOr the modded Version: Navifirm plus 1.1:
http://www.megaupload.com/?d=59PUWQ8RThe firmware you download has to have at least 9 files!!!!
If you don't want to go trhough the trouble of downloading and searching yourself for the firmware get the following one... EURO BLU for N8 debranded of course
language supported: English/Frecnh/German/Italian/Portugues/Spanish
11.12http://www.megaupload.com/?d=AJYTH7POand the Hacked UDA for 11.12
http://www.megaupload.com/?d=BU5TTAD013.16http://www.megaupload.com/?d=GZ73C5CWhacked UDA for 13.16:
http://www.megaupload.com/?d=PKMALMQ814.002http://www.megaupload.com/?d=KFWETQMBHacked UDA for 14.002:
http://www.megaupload.com/?d=JCY6YN13SKIP step 3-4-5 If you downloaded the Firmware version directly3) Open Navifirm, and wait for it to load the Products list, then hit N8 (RM596)
4) Select 11.12 and wait for navifirm to load the Variants list
5) Use the search variants box at the bottom to look for the product code of your phone (you can find the product code on the transparent sticker which was on the back of your N8 when you bought it, mine is 0599857******, 0599857 is the product code),THE FIRMWARE HAS TO HAVE AT LEAST 9 FILES!!! then hit MARK ALL, and then DOWNLOAD WITH THE PROGRAM, and choose the directory where you want to download the OFFICIAL firmware files
6) Once you have downloaded the official firmware files, copy (or extract if you downloaded mines) those files to “C:/Program Files(x86)/Nokia/Phoenix/Products/RM-596″ which is the directory where Phoenix will look to get the files it needs to flash the firmware to your N8
7) Connect your N8 via USB cable and open PHOENIX
Click "manage connections" and select USB (then click apply if not preselected)
Hit File–>Scan Product (Phoenix should at that point have found your n8)
Then hit Flashing–>Firmware Update
8.) In the firmware update screen, you’ll see that Phoenix have found the firmware files of the official firmware you downloaded from navifirm (if it doesn’t find any firmware, add the directory C:/Program Files(x86)/Nokia/Phoenix in all the three boxes in Tools–>Options–>Product Location, and repeat step 8 )
Browse for the location using (...)
now hit REFURBISH
If you don't want to jailbreak your n8 skip step 9 and 109) Now a warning dialog box will appear, telling you that one file is missing. THIS STEP IS THE MOST IMPORTANT. Do not click anything on the warning box, just minimize Phoenix screen, go to the folder where you downloaded the hacked UDA file (decompress the zipped file first), and copy it to C:/Program Files(x86)/Nokia/Phoenix/Products/RM-596 .
10) If it asks you to overwrite say yes, then go back to Phoenix and hit yes on the warning dialog box. If it doesn’t ask you to overwrite the file, rename the OFFICIAL UDA FILE to something else
11) Now go back to the Phoenix’s warning dialog box, and hit YES, and wait for the flashing process to complete
12) Done Now you can install unsigned apps
ENJOY
IMPORTANT:
It is possible that the OVI store won't work at the end of this debranding even though I did not have any pb running it after it, if so, just reinstall it using this:
http://www.megaupload.com/?d=QX1SG33L
Flashing dead phones (Which show only white screen on startup)
1. The procedure is the same for flashing Dead phones.
2. Start Phoenix. Connect your phone with USB Cable [phone is off at this time].
3. Click File>Open Product. Select your RM code from the window that appears. Click OK.
4. Click File> Manage Connections. Select No Connection. Then APPLY and CLOSE.
5. Now straight away click Flashing>Firmware Update.
6. A window will open. Click on Browse button [the one with 3 dots].
7. A window will open with various products and various regions. Choose the region or country of your choice according to the language pack you want to install.
8. Check the option “Dead Phone USB Flashing”.
9. Click Refurbish.
10. Flashing has started.
11. After some seconds flashing will pause asking you to turn your phone ON.
12. Press POWER button of your phone until backlight comes up.
13. Flashing will proceed.
14. Your phone will automatically start when the flashing finishes. After finish you can safely remove your data cable from handset.