some quick instructions for those that want to pop Googles latest and greatest on your Nexus 5.
Download the system files
– Google Factory image: https://developers.google.com/android/nexus/images#hammerhead
if you want/need root, also get
– Latest TWRP Recovery: http://techerrata.com/browse/twrp2/hammerhead
– Chainfires kernel install script: http://download.chainfire.eu/363/CF-Root/CF-Auto-Root/CF-Auto-Root-hammerhead-hammerhead-nexus5.zip
Extract the files from the Factory image, until you have the following files together in one folder
Boot into Bootloader Mode (Power + Volume Down) & run the following commands:
fastboot flash bootloader bootloader-hammerhead-hhz11k.img
fastboot flash boot boot.img
fastboot flash radio radio-hammerhead-m8974a-18.104.22.168.21.img
fastboot flash system system.img (this will take a while!)
fastboot flash recovery openrecovery-twrp-22.214.171.124-hammerhead.img
this next step is optional, but if you want a completely clean flash, or you haven’t done a fresh install recently (ie. before 4.4.4) I recommend doing this for 5.0. Note this will wipe your SD card so make a backup!
fastboot flash userdata userdata.img
Once they are all complete, reboot into recovery and perform a factory reset.
If you need Root, reboot back into fastboot mode and run the Chainfire installer downloaded earlier.
Once your done, reboot your phone.
The first boot will take a while so go make a brew, once its booted your done. enjoy 🙂