1) Extract the SDK into a location where you know it is. For the purpose of this mine is in C:\Android\platform-tools.
The SDK includes :
adb.exe - Windows adb utility
fastboot.exe - Windows fastboot utility
fastboot-windows.exe - Windows fastboot utility
AdbWinApi.dll - adb link library for Windows
AdbWinUsbApi.dll - adb link library for Windows
2) Extract the factory image using a program like winzip or 7zip.
Upon completion, you'll need to extract it again to get to the files we actually need.
When its fully extracted youll see:
bootloader-hammerhead-hhz11k.img
flash-all.bat
flash-all.sh
flash-base.sh
image-hammerhead-ktu84p.zip
radio-hammerhead-m8974a-2.0.50.1.16.img
The important ones are:
bootloader-hammerhead-hhz11k.img
radio-hammerhead-m8974a-2.0.50.1.16.img
image-hammerhead-ktu84p.zip
Unzip image-hammerhead-ktu84p.zip. It contains your system. cache, data, and boot partitions
3) Move the following into your C:\Android\platform-tools folder (where you have your miniSDK files):
bootloader-hammerhead-hhz11k.img
radio-hammerhead-m8974a-2.0.50.1.16.img
boot.img
cache.img
system.img
userdata.img
4) Now hold power+volume down on your phone to enter fastboot. Plug your device into the computers usb port.
5) Enter a command line pointed to your fastboot tool location. If you have a windows 7 or newer computer you can do this easily by going to the folder, and shift+right clicking and selecting "open command window here"
Or you can navigate manually using the command cd
When the command window is open and pointing to the correct place, type "fastboot devices" and hit enter
If it spits out a series of numbers/letters under "connected devices" we know the computer is correctly communicating with your phone. If nothing shows up, your command prompt is either in the wrong location or you have a driver issue.