Please perform this operation on your own RISK!
Here we go guys, Faenil at i8910tuning.com has modified a UDA image (credits go to Il.Socio for providing the tools and CODeRUS for providing the hacked installserver) to let you all have your N8 hacked right now and be able to install unsigned apps!
Grab working version of Phoenix 2010.8 from here:
IF YOU ALREADY KNOW HOW TO FLASH A NOKIA DEVICE, READ HERE:
It is enough to Download the hacked UDA rename it to the name of the UDA image of the firmware of your product code, and flash it using Phoenix!
IF YOU HAVE NEVER FLASHED A NOKIA DEVICE, THEN READ HERE:
1) Download and install Phoenix 2010.8
3) 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) 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 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
Hit File–>Scan Product, and then hit Flashing–>Firmware Update
9) 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 ) , now hit REFURBISH
10) 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 .7z file using peazip or 7zip first), and copy it to C:/Program Files(x86)/Nokia/Phoenix/Products/RM-596 .
11) 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 (for example, if the name of the official UDA file is RM-596_011.012_U01.01_79.92_prd.uda.fpsx, rename it to RM-596_011.012_U01.01_79.92_prd_ORIGINAL.uda.fpsx) and rename the HACKED UDA to the former name of the OFFICIAL UDA FILE (the name of the hacked uda is RM-596_011.012_U03.01_79.92_prd.uda.fpsx, in this case you have to rename it to RM-596_011.012_U01.01_79.92_prd.uda.fpsx, which is the name of the UDA you download from navifirm)
12) Now go back to the Phoenix’s warning dialog box, and hit YES, and wait for the flashing process to complete
13) Done Now you can install unsigned apps
Update: This Firmware has a bug and you won’t be able to start the OVI Store. You need to apply this Fix, in order to run the OVI Store.
Download Instructions - Video Guide