It is very easy to full unlock your phone, but you must know that some knowledge and some nerves are required... Here it goes my experience on unlocking my Nokia Lumia 710 device. Note it has not been tested on Nokia Lumia 800 and that the stock rom with Qualcomm's bootloader is for Lumia 710 devices only.
First we must know if your device has its bootloader unlocked. Nokia phones were previously (and prior to tango updates hold that too) shipped with Qualcomm's boot loader, which allows nand access (needed to flash roms) and allows us to unlock our phones. To do so you must turn your device off, then press Power and Volume Up key till it vibrates. Then connect it to your Windows PC, where you shall get a notification whether saying Nokia Dload (nokia's locked boot loader) or a Explorer pop-up asking you to format a flashdrive (do not do that). If you get the Explorer pop-up your good to go to Step 2 but if you got Nokia's Dload, don't panic.
You are able to downgrade the boot loader using an old rom (this one specific is from Russia) that holds the Qualcomm's unlocked one. For this you'll need Nokia Care Suite and the stock rom files. The stock rom files you might find here (http://forum.xda-developers.com/show....php?t=1599401), a great thread posted by Suzughia where you can learn more about this issue. Anyway, the file you need is in the FAQ session, second question/answer. The NCS file I used you can download here (http://www.4shared.com/file/0YxlvalR...15126304.html?) from my 4shared account*, but for the latest release you'll might check the official site, just google it.
Once you got NCS installed you'll have to go to C:\Program Files\Nokia\Nokia Care Suite\Drivers\ and install WinUSB Drivers x86.msi (or, if you use Windows 64 bit, the respective file). Then go to C:\ProgramData\Nokia\Packages (note that ProgramData is a hiden folder) and create a new folder named Products. Within this folder you'll copy the folder you downloaded (and unzipped, its name shall be, in this case, RM-803).
Now on the start menu you search for Application Launcher, and the app that appears shall call the Nokia Care Application Launcher. There you choose Product Support Tool For Store, a tool that allows you to install any rom from recovery (even the phone you've already unlocked using this tutorial or bricked phones, by theory). Wait to app to load up and connect your device on the computer. Now select the “Automatic Product Selection” box and waits till it recognizes your device. Notice your device might restart once or twice.
Now, in order to install the rom on your phone you must firt open your device model (even if the program indentifies your phone). Go to File>Open Product and select your phone model (in this case the Nokia 710 RM-803). Now go to the sidebar and select Programming>Recovery, on Properties you'll see the information of the rom you downloaded. Select it and then click Start. Ready, your phone is being flashed with the rom 1600.3015.8107.12070, that holds the Qualcomm's bootloader. Wait for it to reboot and you're ready to go to step 2.
Now we're gonna install the custom fully unlocked rom to your phone over the stock rom we just installed. To do so you must have access to a Terminal prompt (wheter on a Linux distribution or on an emulator running on Windows; I strongly recommend you to use Linux, which is more reliable) which will allow you to write the rom image to the phone's flash memory. You'll also have to download the os image, which you can get from Lucifer3006 here (http://forum.xda-developers.com/show....php?t=1654415).
Once you have access to a Terminal prompt and to the os-new.nb file you're ready to go. It is discussed on the thread by Lucifer3006 the use o NSS (a Linux terminal emulator), which I don't have experience to share. For instance, I used Ubuntu 12.04 for the flashing.
First boot your phone into Qualcomm's driver mode (just turn off your device, and then boot up holding power + volume up untill you feel a short vibration and then connect your phone to the computer) . Now you have to know the "address" of your device (that's given by the system). Open up terminal and type:
With this command you'll see a list of the registered blocks of the storage devices on your computer. Usually your device will be the second on listed (in the case you only have your hardrive and your device plugged to the computer) and it is named sdXY, where X is the name of your device and Y is the number of the partition. On my case my device was f.
Now navigate to the folder you saved the os-new.nb file in terminal (in my case I saved on the User's folder, where the terminal opens by default in Ubuntu, the distro I used, or in most Linux distros). To be sure verify if the file is there by typing "ls", it will show a list of the files on that folder. If everything's fine, now you should enter the command that will copy the os-new.nb file to the phone boot memory, so the rom will be literally installed when the phone is booted.
Type this command in:
dd if=./os-new.nb of=/dev/sdX9
Explanation: "dd" is the command that copies the "if" to the "of" partition with low level privilegies. In this case "if" is the os-new.nb file and "of" is the boot partition address of your device. Make sure to replace the X with your device name. For example, my device was named "f", so my address will be of=/dev/sdf9, where sdf9 stands for storage device f, partition 9**. The boot partition of Windows Phone is addressed as the nineth one of the device (it is not an statement).
Once done copying (it will give you no feedback but the blinking square, so when it's done you'll just see the prompt address again) you shall disconnect your device.
In order to boot your device you have to perform a hard reset (this will literally install the os-new.nb to your device). To do so you have to hold down power + volume up + camera key for 10 seconds, then release the power key but still hold the volume up and the camera key for more 5 seconds (this was said in other post I can't remember which, don't know if is the correct way, but it worked for me). If the device does not boot up you can remove the battery and place it again, now just turn it on normally, and it will boot into the custom fully unlocked rom.
Note that the WP Root Tool installed on the rom is the 0.9 version and as for up to today it has expired, so you won't be able to use it unless you set your device date to past August 2012. In Baazar you can install the newer version but for using it you must mark it as trusted in RootManager app included on the mod rom.
Post anything you have to say and if you have a doubt, just ask me and I might help with anything I'm capable of.
Everything I posted here is upon my personal experience only. I do not own any rights over any file posted here through other threads. The responsability for them relies on the threads' holders then.
* I do not own any rights over this program and I just posted a personal link once I wasn't able to recall the original one. Also this is the only file who sucessfully recognized my device upon my experience.
** This is said just to make an example and clearify the idea, it is not its actual meaning for as long as I don't know its actual meaning.
All Links Used Here:
Nokia Care Suite version 2011.51.2.63046 5.0
Get Ubuntu Linux 12.04 for free
Nokia's 710 RM-803 Country Variant Russia direct download link:
How to Interp Unlock Nokia l710 original thread:
RainbownMod v1.4 and older, also the original thread of discussion: